Gang Chen,Tao Fan,Shilong Zhang,Cong Xie,Chunlin Fu,Rongli Gao,Zhenhua Wang,Xiaolin Deng,Peigeng Fan,Wei Cai
(100–x) wt% (0.95BT–0.05BY)–x wt% (0.5MgO–0.5SiO2) (x = 0, 1, 2, 4, 8) ceramics were fabricated by using a solid-state synthesis method. The effects of the MgO–SiO2 doping on the microstructure, the ferroelectric, and the dielectric properties of BT–BY ceramics were investigated in detail. The results show that the relative permittivity initially decreases and then increases again upon the increase in the MgO–SiO2 content. The addition of the MgO–SiO2 glass oxide dopant enhances the frequency and the temperature stability of the relative permittivity of BT–BY ceramics. Moreover, the coercive field and the remnant polarization increase and then decrease with increasing MgO–SiO2 dopant content, while the slim P–E loops are observed when x ≥ 2. The largest values for the remanent polarization (1.2 μC cm−2) and the coercive field (9.18 kV cm−1) are obtained at x = 1. The addition of MgO–SiO2 can induce a small leakage current in the BT–BY ceramic when x ≥ 2. The breakdown strength increases with decreasing grain size when MgO–SiO2 is added moderately. Its value increases from 80 kV cm−1 up to 100 kV cm−1 when x changes from 0 to 8. The energy storage density and efficiency of the (100–x) wt% (0.95BT–0.05BY)–x wt% (0.5MgO–0.5SiO2) ceramics decrease and then increase with increasing x. The maximum values of the electrical energy storage density (0.24 J cm−3) and energy efficiency (85.77%) are obtained when x = 8.
(0.9 – x )BaTiO 3 –0.1BiYbO 3 – x BiAlO 3 ( 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 BiAlO 3 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 ( ε r ) of ceramics is realized by MWS. Incorporated with BiAlO 3 contributes to enhancement of the frequency and temperature stabilities of the dielectric constant for BaTiO 3 –BiYbO 3 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.