Effect of Ca substitution on microwave dielectric properties of BaV2O6 ceramics

Effects of Ca substitution for Ba on the phase composition, microstructure, sintering behavior and microwave dielectric properties of nominal ceramics Ba1-xCaxV2O6 (0.2 x 0.5) were investigated. The XRD, Raman and SEM results revealed that BaV2O6 and CaV2O6 composite ceramics were formed. Nominal ceramics Ba1-xCaxV2O6 could be well densified at about 550 A degrees C via a solid-state reaction method. The microwave dielectric properties exhibited strong dependence on the composition and microstructure. Typically, the Ba0.7Ca0.3V2O6 ceramics sintered at 550 A degrees C exhibited excellent microwave dielectric properties: epsilon(r) = 10.9, Qxf = 17,100 GHz (at 9.9 GHz), and tau(f) = 4 ppm/A degrees C. Meanwhile, Ba0.7Ca0.3V2O6 ceramics also showed good chemical compatibility with Al electrode. These results indicated that the Ba0.7Ca0.3V2O6 ceramics could be a promising candidate for the ULTCC technology.