Effect of Zn/Si Ratio on the Microstructural and Microwave Dielectric Properties of Zn2SiO4Ceramics

Zn 2 SiO 4 ceramics synthesized by the conventional solid-state method exhibited a low Q × f value, possibly due to the formation of a ZnO second phase. However, with a small ZnO reduction from the Zn 2 SiO 4 ceramics, the ZnO second phase disappeared and grain growth occurred due to the formation of a Si-rich liquid phase. Specimens with a large grain size exhibited an improved Q × f value. In particular, the ceramics with nominal composition Zn 1.8 SiO 3.8 sintered at 1300°C exhibited improved microwave dielectric properties of e r = 6.6, Q × f = 147000 GHz, and τ f = -22 ppm/°C.