Influence of B-site rare-earth Yb cation on the crystal structure and microwave dielectric properties of Ca3Yb2Ge3O12 garnet ceramics

摘要

In this work, garnet structured Ca3Yb2Ge3O12 ceramics with a space group of Ia-3d were synthesized by a solidstate reaction method. Rietveld refinement analysis demonstrated that Yb3+with small ionic radius and large electronegativity entered the B-sites and shortened the bond length of B-O and Ge-O. The bond valence and P-VL theory analysis results showed that Ca cations with a weakened rattling effect exerted a critical effect on the dielectric constant, and the Ge-O bond was the main factor that influenced dielectric loss. Ca3Yb2Ge3O12 with a high relative density (98.2%) and excellent microwave dielectric properties (Er= 10.2, Q x f = 98,400 GHz, of = -48 ppm/degrees C) was obtained at 1360 degrees C for 4 h. Furthermore, the intrinsic dielectric constant and dielectric loss (Er =10.12, Q x f = 101,900 GHz) of Ca3Yb2Ge3O12 were obtained by infrared reflectivity spectroscopy.

关键词