Hui-Ping Sun

A New System of Low Temperature Sintering ZnO–SiO2 Dielectric Ceramics

A new ZnO–SiO2 microwave dielectric ceramic system with Li2CO3 and Bi2O3 composite additives was studied. It was difficult to acquire dense ceramics at 1380 °C without sintering aids using the ZnO–SiO2 system. With 5 wt % Li2CO3 and 4 wt % Bi2O3 composite addition, the ZnO–SiO2 system can be sintered well at approximately 900 °C. The dielectric constant of ZnO–SiO2 system decreased with increasing SiO2 content and Q×f value acquired a maximum at a certain SiO2 content. The samples of ZnO–0.6SiO2 with Li2CO3 and Bi2O3 addition sintered at 910 °C for 2 h showed excellent properties such as er=6.65, Q×f=33,000 GHz (at 11 GHz), and τf=-70 ppm/°C.