Rare Earth Ion-Doped Y2.95R0.05MgAl3SiO12 (R = Yb, Y, Dy, Eu, Sm) Garnet-Type Microwave Ceramics for 5G Application

In this work, Y2.95R0.05MgAl3SiO12(R = Yb, Y, Dy, Eu, Sm) microwave single-phase dielectric ceramics were successfully prepared via a conventional ceramic sintering technology by doping a series of rare earth elements (Yb, Y, Dy, Eu, Sm) with different ionic radii for the first time. The effects of A-sites occupied by rare earth elements on the microwave dielectric properties of Y2.95R0.05MgAl3SiO12were studied using crystal structure refinement, a scanning electron microscope (SEM), bond valence theory, P-V-L theory, and infrared reflection spectroscopy. It was found that the ionicity of the Y-O bond, the lattice energy, the bond energy, and the bond valance of the Al(Tet)-O bond had important effects on the microwave dielectric properties. Particularly, the optimum microwave dielectric properties,εr= 9.68,Q×f= 68,866 GHz, andτf= −35.8 ppm/°C, were obtained for Y2.95Dy0.05MgAl3SiO12when sintered at 1575 °C for 6 h, displaying its potential for 5G communication.Keywords:garnet;microwave dielectric properties;P–V–L theory;infrared reflection spectroscopy