Effects of MgO-Doping on Electrical Properties and Microstructure of BaTiO3

Degradation behaviors of Mg-doped BaTiO3 have been studied in terms of oxygen vacancy concentration and microstructural development. Mg-doped BaTiO3 powders were precisely synthesized by the Pechini method. As MgO content was increased to 1.0 mol%, Curie points moved to lower temperatures and dielectric constants decreased. The specimens doped with MgO showed higher leakage currents under the continuously applied dc field at a high temperature (100°C) during the aging process, compared with the undoped BaTiO3. With low levels of MgO (<1.0 mol%), the microstructure is similar to that of undoped BaTiO3, whereas a significant reduction in grain size was observed with higher levels (>2.0 mol%).