Effect of B2O3 on the sintering and microwave dielectric properties of M-phase LiNb0.6Ti0.5O3 ceramics

The effect of B2O3 addition on the sintering, microstructure and the microwave dielectric properties of LiNb0.6Ti0.5O3 ceramics have been investigated. It is found that low-level doping of B2O3 (≤2 wt.%) can significantly improve the densification and dielectric properties of LiNb0.6Ti0.5O3 ceramics. Due to the liquid phase effect of B2O3 addition, LiNb0.6Ti0.5O3 ceramics could be sintered to a theoretical density higher than 95% even at 880 °C. No secondary phase was observed for the B2O3-doped ceramics. There is no obvious degradation in dielectric properties for the ceramics with B2O3 additions. In the case of 1 wt.% B2O3 addition, the ceramics sintered at 880 °C show good microwave dielectric properties of ɛr = 70, Q × f = 5400 GHz, τf = −6.39 ppm/°C. It represents that the ceramics could be promising for multilayer low-temperature co-fired ceramics (LTCC) applications.