Lowered sintering temperature and improved microwave dielectric properties in a vanadium tantalate via in-situ adjusting V 5+ /Ta 5+ molar ratio

Compositional modification engineering was designed to simultaneously reduce the sintering temperature and improve the dielectric properties of BaTa 2 V 2 O 11 via in-situ adjusting the V 5+ /Ta 5+ molar ratio. A series of BaTa 2- x V 2+ x O 11 ceramics, fabricated by a solid-state reaction method, were characterized for structural evolution and dielectric properties variations. In-situ adjusting V 5+ /Ta 5+ molar ratio significantly lowered the sintering temperature of BaTa 2 V 2 O 11 and prominently improved the temperature stability of resonance frequency which is explained by the dielectric dilution theory. Competitive microwave dielectric properties with ε r = 11.5–25.9, Q × f = 22,172–42,660 GHz, and τ f = 42.4–74.6 ppm/ºC were achieved in the BaTa 2- x V 2+ x O 11 ceramics sintered at 620–840 oC. All the results indicate that the molar ratio of V 5+ is primarily responsible for improving the densification behavior and dielectric characteristics of BaTa 2- x V 2+ x O 11 , which in turn increases the appropriateness in further practical applications.