Effects of Sintering Method and BiAlO3 Dopant on Dielectric Relaxation and Energy Storage Properties of BaTiO3–BiYbO3 Ceramics

Abstract

(0.9 – x)BaTiO3–0.1BiYbO3–xBiAlO3 (x = 0, 0.02, 0.04, and 0.08) lead‐free ferroelectric ceramics are synthesized using conventional sintering (CS) and microwave sintering (MWS) methods. The microstructure, dielectric and ferroelectric properties, relaxation behavior, and energy storage properties are investigated systematically. X‐ray diffraction (XRD) patterns show a single perovskite phase for all samples. Scanning electron microscope (SEM) images indicate that MWS method can impede the grain growth, whereas the introduction of BiAlO3 can lead to the increase in the grain size. Dielectric measurements reveal that an obvious dielectric relaxation behavior can be strengthened by MWS, and the improvement of the dielectric constant (εr) of ceramics is realized by MWS. Incorporated with BiAlO3 contributes to enhancement of the frequency and temperature stabilities of the dielectric constant for BaTiO3–BiYbO3 ceramics. The slim hysteresis loops are observed, and the maximum polarization of the sample sintered by MWS is higher than that sintered by CS. The MWS samples possess a higher energy density which is about 2 times larger than that of CS samples, and the largest energy storage density ≈0.86 J cm−3 and energy storage efficiency ≈97.44% are, respectively, obtained at x = 0 and 0.04 for MWS ceramics.