Effects of Sintering Method and BaTiO 3 Dopant on the Microstructure and Electric Properties of Bi (Fe 0.9 Al 0.05 Yb 0.05 ) O 3 -Based Ceramics

The (1 − x ) Bi (Fe 0.9 Al 0.05 Yb 0.05 ) O 3 – x BaTiO 3 (BFAYO- x BTO) ceramics were synthesized by microwave sintering (MWS) and conventional sintering (CS) methods. The crystal structure, surface morphology, dielectric and ferroelectric properties were investigated. XRD patterns show that BTO tetragonal and BFO rhombohedral phases coexist in both MWS and CS samples, and that the diffraction peaks of MWS samples shift to lower angles due to the larger ionic radius of Ba 2+ compared with Bi 3+ . The lattice constant of BFAYO- x BTO ceramics increases with the increase of BTO content. It was found that the average grain size of the MWS ceramic is much smaller than that of the CS ceramic. Dielectric measurements reveal that the dielectric loss and dielectric constant increase with BTO content increasing. The introduction of BTO into BFAYO-based ceramic contribute to the enhancement of the dielectric relaxation behavior. The P – E hysteresis loops demonstrate that the remnant polarization ( P r ) and the coercive field ( E C ) of the MWS samples are smaller than those of the CS samples. P r and E C first increase, then decrease and then increase again with the increase of BTO content. The maximum and minimum values of the remnant polarization were obtained at x = 0.25 and 0.3, respectively.