Effect of B2O3 and CuO additions on the sintering temperature and microwave dielectric properties of 3Li2O-Nb2O5-3TiO2 ceramics

The effects of B2O3-CuO (BCu, the weight ratio of B2O3 to CuO is 1:1) addition on the sintering behavior, microstructure, and the microwave dielectric properties of 3Li(2)O-Nb2O5-3TiO(2) (LNT) ceramics have been investigated. The low-amount addition of BCu can effectively lower the sintering temperature of LNT ceramics from 1125 to 900 A degrees C and induce no obvious degradation of the microwave dielectric properties. Typically, the 2 wt% BCu-added ceramic sintered at 900 A degrees C has better microwave dielectric properties of epsilon (r) = 50.1, Q x f = 8300 GHz, tau (f) = 35 ppm/A degrees C. Silver powders were cofired with the dielectric under air atmosphere at 900 A degrees C. The SEM and EDS analysis showed no reaction between the dielectric ceramic and silver powders. This result shows that the LNT dielectric materials are good candidates for LTCC applications with silver electrode.