Low temperature solid-phase synthesis of tetragonal BaTiO_3 powders and its characterization

摘要

We report an alternative synthesis route for tetragonal and submicron barium titanate particles through a low temperature isothermal heat treatment of a precursor powder obtained from the BaO_2-TiO_2-C mixture utilizing combustion synthesis technique. Effort has been concentrated on the investigation and optimization of the synthesis process including combustion temperature and velocity, heat treatment procedure, and the characteristics of the powder obtained. It was shown that precursor powder prepared by the combustion method easily transformed to the tetragonal BaTiO_3 starting from 700 ℃. Characterization of the products was performed by powder X-ray diffraction, scanning electron microscopy (SEM) and BET. From the results, it has been found that the formation of tetragonal BaTiO_3 powder at low temperature is conditioned by high chemical activity and specific characteristics of combustion products. The BaTiO_3 specimens were found to possess high dielectric constant and low dissipation factor at room temperature.