Preparation and ferroelectric properties of MnO_2 doped BaTi_2O_5 ceramics by spark plasma sintering from the solid-state-calcined powder

摘要

Dense BaTi_2O_5 are fabricated from the conventional calcined powder by using spark plasma sintering and by adding MnO_2 as a dopant. The effects of the sintering temperature and the amount of MnO_2 on the phase purity are symmetrically investigated. A pure BaTi_2O_5 phase is obtained under a condition with the sintering temperature of 1,055 ℃ and the amount of MnO_2 doping of 0.2 wt% from the conventional powder calcined at 950 ℃. The relative density of that ceramics is 98 %. The temperature dependence of dielectric property shows the Curie temperature (T_c) of 446 ℃ with the peak value of 450. Besides, the ceramics polarization of 0.63 μC/cm~2 and the coercive field of 2.0 kV/cm at room temperature, respectively.