Effects of impurities on the properties of BaTiO3 synthesized from barium titanyl oxalate

The effects of impurities, such as H+/Cl− and Zr4+, on the tetragonality (=c/a) of BaTiO3 were examined to determine their effect on the synthesis of nano-sized particles with a high dielectric constant. The quantity of incorporated impurities was adjusted by controlling the milling and washing processes, which are essential for the preparation of BaTiO3 using an oxalate method. The tetragonality decreased with increasing impurity concentration, which can be actual proof of the assumption that impurities decrease the tetragonality due to the enhanced internal strain fields. Moreover, the experimental results showing a tetragonality of 1.0068 for a particle size of 119 nm suggest that the dielectric properties of BaTiO3 prepared by the oxalate route may be comparable with those prepared by solid-state reactions by optimizing the process parameters.