EFFECTS OF B2O3 ADDITION ON SINTERING BEHAVIOR AND MICROWAVE DIELECTRIC PROPERTIES OF Mg4Ta2O9 CERAMICS PREPARED BY THE SOL–GEL METHOD

Sintering characteristics and microwave dielectric properties of Mg4Ta2O9–5wt% B2O3 ceramics were investigated. With the sintering temperature increasing in the range of 1100∘C–1350∘C, the apparent density, er and Q⋅f values increased firstly and then saturated at 1250∘C with excellent microwave properties: er∼12.1, Q⋅f∼77,575GHz and τf∼−40ppm/∘C. Compared to the pure MT ceramics, the B2O3 additives effectively decreased the sintering temperature of MT ceramics and had no detrimental effect on the properties of the MT ceramics due to the liquid phase effect.