Structure and dielectric properties of lower valence compensation for Ba1-xNax(FeTa)0.5O3 by reaction sintering process

ABSTRACTComplex perovskite oxides of Ba1-xNax(FeTa)0.5O3 (BNFT, x = 2, 4, 6, 8, 14, and 20 mole%) dielectric ceramics doped with lower valence compensation ions were prepared by a reaction-sintering process. The BNFT dielectrics were sintered at 1300°C for 8 h without calcinations involved. Due to low melting point of Na2CO3, the sintering temperature of dielectric decreased. The density of sintered dielectrics increased with increasing Na+ ion concentration and it cause BNFT dielectric surface glossy. The relative densities of sintered dielectrics were higher than 89.5%. The dielectric constant of Ba0.96Na0.04(FeTa)0.5O3 1300°C sintered ceramic was about 9 × 105, measured at room temperature at frequency of 1 kHz. The temperature-dependent loss curves measured in temperature range of −15∼90°C and frequency of 1 k∼1 MHz indicated that the samples exhibit a typical relaxor behavior with a broad temperature range which was contributed by orientation and space charge polarization.