Low-temperature sintering and microwave dielectric properties of ZnZrNb2O8 ceramics with BaCu(B2O5) addition

The effects of BaCu(B2O5) doping on the phase structure, sintering characteristics and microwave dielectric properties of ZnZrNb2O8 ceramics were investigated. Only a single-phase, i.e. ZnZrNb2O8 is formed when BaCu(B2O5) content is ≤3 wt%. Small amount of Ba3Nb8O21 and BaNb2O6 in second phases occurred with further increase in BaCu(B2O5) content. The addition of BaCu(B2O5) can effectively lower the sintering temperature of ZnZrNb2O8 ceramics from 1200 to 950 °C due to liquid phase sintering. ZnZrNb2O8 ceramics with 3 wt% BaCu(B2O5) sintered at 950 °C for 4 h could reach dense structure and exhibit good microwave dielectric properties such as εr=28.4, Q×f=56,720 GHz and τf =−53 ppm/°C. In addition, the ceramics are compatible with Ag electrodes, and therefore, suitable for low-temperature co-fired ceramics (LTCC) application.