Synthesis, phase composition and modified microwave dielectric properties of Mg2+ substituted Zn2SiO4 ceramics with uniform microstructure

Zn2SiO4 ceramics were synthesized by the traditional solid-state process. The effect of Mg2+ substitution on sintering process, phase composition, morphology and microwave dielectric properties were investigated. Doped with different amounts of Mg2+ ion, the sintering temperature can be decreased to 1250 °C from 1350 °C. X-ray diffraction (XRD) patterns showed that there were no second phase appeared. Scanning Electron Microscope (SEM) images proved that moderate substitution of Mg2+ ion could make contribution to the grain compactness in (Zn1−xMgx)2SiO4 ceramics. The microwave dielectric properties of the ceramics strongly depended on the substitution content and sintering temperature. The εr values were related to the density and Q × f values were affected by the grain growth. Remarkably, the (Zn0.6Mg0.4)2SiO4 ceramics sintered at 1250 °C presented excellent microwave properties: εr = 6.097, Q × f = 129,991 GHz and τf = −49.18 ppm °C−1.