Influence of sintering method on microstructure, electrical and magnetic properties of BiFeO3–BaTiO3 solid solution ceramics

The (1-x)BiFeO3-xBaTiO3 (short for (1-x)BFO-xBTO, x = 0.2–0.4) ceramics were prepared by solid-state reaction with microwave sintering (MWS) and conventional sintering (CS) methods. The crystal structure, microstructures, dielectric properties, ferroelectric properties, and magnetic properties of BFO-BTO ceramics sintered by MWS and CS were systematically investigated. It is found that the MWS can effectively decrease the grain size and enhance the compactness of BFO-BTO ceramics. The X-ray diffraction (XRD) results confirm that all ceramics exhibit a single perovskite structure, and the phase transforms from rhombohedral in BiFeO3-rich compositions to pseudo-cubic phase gradually as x increases. Introducing BTO into BFO can strengthen its dielectric relaxation behavior. Compared with CS, the MWS samples have a lower remanent polarization (Pr) and a smaller coercive field (Ec) under the same electric field. Therefore, MWS contributes to the decrease of dielectric loss. Addition of BTO can contribute to the reduction of the coercive force (Hc) of BFO-based ceramic, and so decrease the hysteresisloss. At the same time, its remanent magnetization (Mr) value can be decreased by introducing BTO into BFO and using MWS method. The present research provides a route for decreasing the dielectric loss and hysteresis loss of BiFeO3-based ceramics using the MWS method.