Lowered sintering temperature and improved microwave dielectric properties in a vanadium tantalate via in-situ adjusting V5+/Ta5+ molar ratio

Abstract

Compositional modification engineering was designed to simultaneously reduce the sintering temperature and improve the dielectric properties of BaTa 2 V 2 O 11 via insitu 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 e r = 11.5-25.9, Q 9 f = 22,172-42,660 GHz, and s f = 42.4-74.6 ppm/8C were achieved in the BaTa 2x 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.