Dielectric Behaviour of BaTiO3 Prepared by Sol-Gel Technique when Exposed to Different Oxygen Concentrations

The dielectric properties of batio3 powders prepared by a low temperature aqueous route when exposed to different oxygen concentrations have been studied by means of impedance spectroscopy. due to the differences of solubility of ba and ti in aqueous solutions, deviations from stoichiometric ratios (a 10% excess) and higher solution ph (ph~13) were necessary. xrd traces and tg-dta curves show the formation of nearly phase-pure batio3 with higher calcinations temperatures promoting greater crystallinities. dielectric measurements using impedance spectroscopy show the samples to consist of more than one electrical element including a low resistivity core, a high capacitance grain boundary and a ferroelectric bulk component. exposing the samples to different oxygen concentrations caused a slight increase in resistivities with increasing oxygen concentration, which was attributed to the oxygen stoichiometry. a greater increase in the capacitance of the grain boundary component was also observed compared to the ferroelectric bulk