Low-temperature sintering and microwave dielectric properties of BaO-0.15ZnO-4TiO_2 ceramics with Li_2O-B_2O_3-SiO_2 addition

摘要

Li_2O-B_2O_3-SiO_2 (LBS) synthesized via a solid-state reaction process was chosen as a novel sintering aid for BaO-0.15ZnO-4TiO_2 (BZT) ceramics and compared with LBS glass. The influence of LBS on the sintering behaviors, phase evolution, microstructure and microwave dielectric properties of the resulting BZT ceramics have been investigated in detail. The addition of LBS significantly lowers the sintering temperature of the BZT ceramics from 1150 to 900 ℃ without damaging its microwave dielectric properties. Small amount of LBS promote the densification of BZT ceramic and improve the dielectric properties. However, excessive LBS additions lead to growth of abnormal grain, deteriorating the dielectric properties of the BZT ceramic. The BZT ceramics doped with 8 wt% LBS addition could be well sintered at 900 ℃ for 0.5 h and show excellent microwave dielectric properties of: ε_r = 27.72, Q × f = 20,381 GHz, τ_f = 5.18 ppm/℃.