Structure and dielectric properties of Bi2O3 doped BaTiO3-(Na1/4Bi3/4)(Mg1/4Ti3/4)O3 lead-free ceramics

Bi₂O₃ doped BaTiO₃-(Na_1/4Bi_3/4)(Mg_1/4Ti_3/4)O₃ (BT-NBMT) polycrystalline ceramics were prepared by solid state reaction method. The effects of Bi₂O₃ additive on the microstructure and dielectric properties of BT-NBMT ceramics were investigated. The Bi₂O₃ effectively lowered the sintering temperature and improved the bulk density of BT-NBMT ceramics. The low-temperature stability first improved and then deteriorated with increasing Bi₂O₃ concentration. The core-shell microstructure undertook responsibility for the good dielectric temperature stability. The dielectric ceramic samples with good permittivity and low dielectric loss were obtained at a moderated sintering temperature. The results also suggest that the developed BT-NBMT ceramics may serve as a promising candidate for multilayer ceramic capacitors.