Effect of silica sintering additive on the sintering behavior and dielectric properties of strontium barium niobate ceramics

Sr0.5Ba0.5Nb2O6 powders were prepared in the partial coprecipitation method. Using amorphous SiO2 as the sintering additive, Sr0.5Ba0.5Nb2O6 ceramics were sintered at different temperatures and the effects of the additive on the sintering behaviors and dielectric properties were studied. The phase structure, microstructure and dielectric properties of the samples were investigated in X-ray diffraction (XRD), SEM and LCR analyzer respectively. The results indicated that the amorphous SiO2 additive could accelerate the pore elimination, shorten the sintering time and enhance the density for Sr0.5Ba0.5Nb2O6 ceramics. The well development of microstructure promoted by the additives can result in the improvement of the dielectric constant and the weakening of the relax behavior. With the help of the additive of 1.5 wt.%, the relative density of the sample sintered at 1300 °C only for 2 h can reached 94.3% and the dielectric constant was up to 4322.