Effects of BiAlO3 dopant and sintering method on microstructure, dielectric relaxation characteristic and ferroelectric properties of BaTiO3-based ceramics

(1 − x)BaTiO3–xBiAlO3 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 BiAlO3 into BaTiO3 and the MWS method result in the reduction of the grain size and the porosity of BaTiO3 ceramic. This leads to the enhanced diffuse transition and frequency dispersion. The dielectric constant and loss decrease with increasing the BiAlO3 content, and the temperature and the frequency stabilities are enhanced by introducing BiAlO3 into BaTiO3. The remnant polarization (Pr) increases initially and then decreases with the increase of BiAlO3 content, the maximum values of Pr (9.5 μC/cm2 for CS and 7.27 μC/cm2 for MWS) are obtained at x = 0.02. The addition of BiAlO3 can elevate the variation of polarization ΔP (Pmax − Pr), its maximum values (12.56 μC/cm2 for CS ceramic and 12.2 μC/cm2 for MWS ceramic) are acquired at x = 0.04, 0.08, respectively. The energy storage properties indicate that the energy storage density (Wrec) increases, while the energy storage efficiency (η) firstly decreases and then increases with the increase of x.