Crystal structure and microwave dielectric properties of low-permittivity Sr2MgSi2O7 ceramic

Low-permittivity Sr2MgSi2O7 ceramics with tetragonal crystal structure were prepared through the conventional solid-state method. X-ray diffraction patterns and scanning electron microscopy were used to analyze the phase and micromorphology of the specimens sintered at temperature from 1260 to 1320 degrees C. The bond ionicity, lattice energy and bond energy of Sr2MgSi2O7 ceramics were calculated to investigate the relationships between microwave dielectric properties and microstructures. Optimum microwave dielectric properties were obtained when the sample was sintered at 1280 degrees C for 4h: epsilon(r)=6.85, Qxf(0)=22,530GHz (f=9.20GHz), (f)=-32ppm/degrees C.