Effects of BiAlO 3 dopant and sintering method on microstructure, dielectric relaxation characteristic and ferroelectric properties of BaTiO 3 -based ceramics

(1 − x )BaTiO 3 – x BiAlO 3 relaxor ferroelectric ceramics were prepared by the conventional sintering (CS) and the microwave sintering (MWS) methods, respectively. The microstructure, the dielectric properties, the relaxation characteristic, the ferroelectric and the energy storage properties were investigated in detail. The results show that a single perovskite phase exists in ceramic samples sintered by CS and MWS. The addition of BiAlO 3 into BaTiO 3 and the MWS method result in the reduction of the grain size and the porosity of BaTiO 3 ceramic. This leads to the enhanced diffuse transition and frequency dispersion. The dielectric constant and loss decrease with increasing the BiAlO 3 content, and the temperature and the frequency stabilities are enhanced by introducing BiAlO 3 into BaTiO 3 . The remnant polarization ( P r ) increases initially and then decreases with the increase of BiAlO 3 content, the maximum values of P r (9.5 μC/cm 2 for CS and 7.27 μC/cm 2 for MWS) are obtained at x = 0.02. The addition of BiAlO 3 can elevate the variation of polarization Δ P ( P max − P r ), its maximum values (12.56 μC/cm 2 for CS ceramic and 12.2 μC/cm 2 for MWS ceramic) are acquired at x = 0.04, 0.08, respectively. The energy storage properties indicate that the energy storage density ( W rec ) increases, while the energy storage efficiency ( η ) firstly decreases and then increases with the increase of x .