Low-temperature sintering and microwave dielectric properties of ZnZrNb_2O_8 ceramics with BaCu(B_2O_5) addition

摘要

The effects of BaCu(B_2O_5) doping on the phase structure, sintering characteristics and microwave dielectric properties of ZnZrNb_2O_8 ceramics were investigated. Only a single-phase, i.e. ZnZrNb_2O_8 is formed when BaCu(B_2O_5) content is ≤ 3 wt%. Small amount of Ba_3Nb_8O_(21) and BaNb_2O_6 in second phases occurred with further increase in BaCu(B_2O_5) content. The addition of BaCu(B_2O_5) can effectively lower the sintering temperature of ZnZrNb_2O_8 ceramics from 1200 to 950 °C due to liquid phase sintering. ZnZrNb_2O_8 ceramics with 3 wt% BaCu(B_2O_5) sintered at 950 °C for 4h could reach dense structure and exhibit good microwave dielectric properties such as ε_r=28.4, Q × f =56,720 GHz and τ_f = - 53 ppm/ °C. In addition, the ceramics are compatible with Ag electrodes, and therefore, suitable for low-temperature co-fired ceramics (LTCC) application.