Effect of the B2O3 addition on the sintering behavior and microwave dielectric properties of Ba3(VO4)2-Zn1.87SiO3.87 composite ceramics

The effect of the B2O3 addition on the low-temperature sintering, microstructure and microwave dielectric properties of the Ba3(VO4)2-Zn1.87SiO3.87 composite ceramics was investigated. The results indicate that the addition of B2O3 can effectively promote the densification and further improve the microwave dielectric properties of the composite. The low-temperature sintering mechanism was ascribed to the formation of the liquid phase owing to the reaction between the additive B2O3 and the residual SiO2 in the composite. B2O3-SiO2 liquid phases can not only lower the sintering temperature, but also speed up the grain growth of the composite ceramics. The rapid grain growth occurs as the B2O3 content is more than 6 wt%. The 3 wt% B2O3 doped 0.5Ba3(VO4)2-0.5Zn1.87SiO3.87 ceramics can be well sintered at 925 °C and exhibit excellent microwave dielectric properties of Q×f∼40,800 GHz, εr∼10 and τf∼0.5 ppm/°C.