Structure dependence of microwave dielectric properties in Zn2-xSiO4-x-xCuO ceramics

Abstract

In this work, the Zn2-xSiO4-x-xCuO (x = 0, 0.04, 0.08, 0.12, 0.16 and 0.20) ceramics were synthesized through solid state reaction. The dependence of microwave dielectric properties on the structure was investigated through X-ray diffraction (XRD) with Rietveld refinements, Scanning electron microscope (SEM) and Raman spectra. The melting of CuO can reduce the densification temperature of Zn2-xSiO4-x ceramics. In comparison with x = 0, the x = 0.08 ceramics were densified at 1150℃ and the excellent microwave dielectric properties with low dielectric constant (εr = 6.01), high quality factor (Qf = 105 500 GHz) and τf = −28 ppm/°C, were obtained. The εr, Qf and τf value are dominated by covalency of Si-O bond and secondary phase, crystallinity and lattice energy, respectively. This provides a theoretical basis to further adjust the microwave dielectric property (especially τf value) from the structural point of view.