Low-temperature sintering-microwave dielectric property relations in Ba3(VO4)2 ceramic

The Ba3(VO4)2-x wt.%B2O3 (x = 0-5) ceramics were prepared by the solid state reaction method in order to reduce the sintering temperature. The saturated bulk densities of Ba3(VO4)2-x wt.%B2O3 ceramics were shifted toward lower sintering temperatures with increased the amounts of B2O3 doping, and then an improvement in the quality factor (Q·f) of the samples was recognized at the lower sintering temperatures. As a result, the Q·f value of 41,065 GH, the ɛr of 12.5 and the τf value of 38.8 ppm/°C were obtained in the sample of the Ba3(VO4)2-0.5 wt.%B2O3 ceramic sintered at the temperature of 950 °C. However, the Q·f values of the sample with B2O3 higher than that of 3 wt.% additions decreased because of the formation of secondary phase and abnormal grain growth of the sample. As for the chemical compatibility with silver, no secondary phase was detected in the XRPD pattern when the mixtures of Ba3(VO4)2-1 wt.%B2O3 ceramics and Ag powders were heat-treated at 900 °C for 1 h in air.