Microwave dielectric properties and low temperature sintering of the ZnO–V2O5 doped Ba3Ti2(Mg1/3Nb2/3)2Nb4O21 ceramics

The ZnO and V2O5 co-doped Ba3Ti2(Mg1/3Nb2/3)2Nb4O21 (BTMNN-2) microwave dielectric ceramics were successfully prepared via a conventional solid-state reaction method. The effect of the 2 ZnO–V2O5 complex additive on the sintering temperature and microwave dielectric properties was specially investigated. The X-ray diffraction analysis reveals that the BTMNN-2 ceramics doped with 2 ZnO–V2O5 form a single hexagonal structure phase without visible secondary phases. A small amount of 2 ZnO–V2O5 additive can significantly lower the sintering temperature of BTMNN-2 ceramics owing to the formation of a liquid phase in the BTMNN-2 matrix, as clearly evidenced by the SEM micrographs. Meanwhile, the experimental results show that the microwave dielectric properties of the samples were strongly dependent on the densification, crystalline phases, and grain size. The 5 wt% 2 ZnO–V2O5 doped BTMNN-2 ceramics can be sintered at 900 °C and own good microwave dielectric properties of εr=47, Q×f=10,500 GHz and τf=16 ppm/°C, showing a potential for applications in mid-permittivity low temperature co-fired ceramics.