Microstructure, dielectric and ferroelectric properties of (1−x) BaTiO₃–xBiYbO₃ ceramics fabricated by conventional and microwave sintering methods

(1−x) BaTiO₃–xBiYbO₃ (abbreviated as (1−x) BT−xBY, x = 0, 0.03, 0.06 and 0.09) ferroelectric ceramics have been fabricated by conventional sintering (CS) and microwave sintering (MWS) methods. The microstructure, dielectric and ferroelectric properties of (1−x) BT–xBY ceramics have been investigated systematically. X-ray diffraction patterns indicate all samples possess single perovskite phase and the crystal structure transforms from tetragonal to pseudo-cubic phase with increasing x. It can be also found that denser microstructure and finer grains can be obtained by MWS compared to CS as indicated by scanning electron microscopy. Dielectric measurements reveal that the addition of BY can lead to an obvious relaxation behavior in all samples, and the relaxation characteristics of MWS samples are stronger than those of CS samples. Moreover, the dielectric constant decreases with increasing BY content and the temperature stability and frequency stability of dielectric properties can be enhanced by using MWS method and addition of BY. P–E hysteresis loops become slimmer with the increase of BY content, and the ferroelectric properties of MWS samples are similar to those of CS samples. The leakage current of MWS sample is smaller than that of CS sample from J–E curve. The energy storage efficiency (η) increases with increasing BY content, while the energy storage density (U) increases and then decreases, U_max is obtained at x = 0.06. These results demonstrate that MWS technique and moderate BY content are effective methods to prepare materials for energy storage application.