Effect of ZnO and B2O3 on the sintering temperature and microwave dielectric properties of LiNb0.6Ti0.5O3 ceramics

Dielectric ceramics LiNb0.6Ti0.5O3 (LNT), containing ZnO–B2O3 (ZB) as sintering aids were prepared and investigated on microstructures and microwave dielectric properties. With addition of low amount of ZB (up to 3.0 wt%), the sintering temperature of the LNT ceramics could be lowered down to around 875 °C. A secondary phase was observed at the 3 wt% ZB addition. The addition of ZB does not induce much degradation on the microwave dielectric properties but adjusts the τf value to near zero. Typically, the excellent microwave dielectric properties of ɛr = 70, Q × f = 5900 GHz, and τf = −4.5 ppm/°C were obtained for the 1 wt% ZB-doped sample sintered at 875 °C. Silver powders were co-fired with the dielectric under air atmosphere at 900 °C. The XRD and EDS analysis show no reaction between the dielectric ceramic and silver powders. This result shows that the Li1.0Nb0.6Ti0.5O3 dielectric materials are good candidates for LTCC applications with silver electrode.