A novel low dielectric constant Sr2Ga2GeO7 microwave dielectric ceramic with tetragonal structure

In this paper, Sr2Ga2GeO7 (SGG) ceramics were prepared by the solid-state method, and their microwave dielectric properties were studied. The XRD and TEM analyses show that the ceramic samples all acknowledged a tetragonal structure with the P-412 m (113) space group. The refinement results show that the lattice parameters of the ceramics sintered at 1360 degrees C are a = b = 8.04553 & ANGS;, c = 5.39084 & ANGS; and V = 348.9517 & ANGS;3. The Sr2Ga2GeO7 ceramics sintered at 1360 degrees C have a compact microstructure, and the optimum relative density is 97.5 %. Raman spectroscopy exhibited that the quality factor shows a close connection with the FWHM of the A1 g mode at 785 cm-1. The microwave dielectric properties of Sr2Ga2GeO7 ceramics sintered at 1360 degrees C were found to be er = 6.52, Q x f = 32,685 GHz (f = 12.99 GHz), and zf = -37.15 ppm/degrees C.