Novel Sr3Y2Ge3O12 microwave ceramics: Sintering behavior, phase composition, microstructure and dielectric properties

Sr3Y2Ge3O12 ceramics were prepared by a solid-phase reaction method. X-ray diffraction patterns and Rietveld refinement showed that the ceramics have a cubic garnet structure belonging to the Ia-3d space group. The scanning electron microscopy analysis illustrated that the ceramic material is relatively dense and homogeneous with clear grain boundaries at the optimum sintering temperature. The dielectric constant and quality factor has a strong correlation with bulk density. The Sr3Y2Ge3O12 ceramic sintered at 1275 degrees C exhibited good microwave dielectric properties: epsilon r = 7.23, Q x f = 27203 GHz and tau f =-26.79 ppm/degrees C. The value of Q x f increases to 45000 GHz when the ambient temperature rises to 150 degrees C. Besides, a high bulk density of 4.68 g/cm3 and a relative density of 92.9% were also obtained.

Automated summary

Sr3Y2Ge3O12 ceramics with cubic garnet structure were prepared by solid-phase reaction. The ceramics exhibited relatively dense and homogeneous microstructures with clear grain boundaries at the optimum sintering temperature, as confirmed by X-ray diffraction and scanning electron microscopy. The dielectric constant and quality factor showed a strong correlation with bulk density. The sintered Sr3Y2Ge3O12 ceramic at 1275 degrees C demonstrated good microwave dielectric properties, with epsilon r = 7.23, Q x f = 27203 GHz, and tau f =-26.79 ppm/degrees C. The value of Q x f increased to 45000 GHz at an ambient temperature of 150 degrees C. A high bulk density of 4.68 g/cm3 and a relative density of 92.9% were also achieved.