Electrical investigations of BaTiO 3 ceramics with Ba/Ti contents under influence of temperature

Electrical properties of the solid state sintered BaTiO3 ceramics at 0.98 and 0.94 Ba/Ti molar ratio are investigated perhaps for the first time in the wide range of temperatures (40–700 °C) at 1 kHz frequency. The studies were focused to find the controlling parameters, resistance and understanding of the conduction process. BaTiO3 ceramics were perovskite ferroelectric materials, showed cubic and tetragonal crystal structures (Pm-3m, P4MM) at room temperature. Thermogravimetric and differential scanning calorimetric analysis (TGA-DSC) revealed melting temperatures, weight losses and crystallization of the as ground powders. Curie temperature (Tc) increased from120–130 °C with decreasing Ba/Ti contents. Dielectric anomalies with relaxor behavior were observed. Resistivity decreased with increasing temperature, all specimens showed semiconductor behavior with negative temperature coefficient of resistivity (NTCR) characteristics. At 0.98 molar ratio, BaTiO3 ceramics were found to be more conductive and less resistive. Conductivity followed Arrhenius Law with Ea = 0.2948–0.3284 and 0.967–1.189 eV which can be attributed to ionic conduction followed by single ionized and doubly ionized oxygen vacancies. Well defined hysteresis P-E loops under electric fields showed ferroelectric characteristics.