Perovskite Materials

Two synthesis ways including sol-gel method starting from the aqueous solutions for the preparation of BaTiO3 ceramics has been developed. Homogeneous monolithic gels are achieved by complexing barium ions with tartaric acid, and using PVA as esterification agent.

According to TG and IR measurements, the formation of BaTiO3 occurs probably via the decomposition of the intermediate oxycarbonate. X-ray diffraction and SEM analyses of the ceramics obtained revealed that mainly a tetragonal phase of BaTiO3 was formed during calcination, but an impurity phase of monoclinic Ba2TiO4 was found as well.

The synthesized barium titanate exhibited a PTCR effect, having a Tc about 125 °C. The resistivity jump of obtained samples depends on cooling rate during high-temperature synthesis, and increased as the cooling rate decreased.