Effect of Bi2O3 Addition on the Sintering Temperature and Microwave Dielectric Properties of Zn2SiO4 Ceramics

Bi2O3 was added to a nominal composition of Zn1.8SiO3.8 (ZS) ceramics to decrease their sintering temperature. When the Bi2O3 content was <8.0 mol%, a porous microstructure with Bi4(SiO4)3 and SiO2 second phases was developed in the specimen sintered at 885°C. However, when the Bi2O3 content exceeded 8.0 mol%, a liquid phase, which formed during sintering at temperatures below 900°C, assisted the densification of the ZS ceramics. Good microwave dielectric properties of Q × f=12,600 GHz, ɛr=7.6, and τf=−22 ppm/°C were obtained from the specimen with 8.0 mol% Bi2O3 sintered at 885°C for 2 h.