A novel low-permittivity Lu2MgAl4SiO12 microwave dielectric ceramic with garnet-type structure

For the timely transmission of signals, the research of low dielectric constant microwave ceramics is essential. In this study, a new type of low-permittivity Lu2MgAl4SiO12 microwave dielectric ceramic was prepared by traditional solid-phase method. The successful synthesis of Lu2MgAl4SiO12 ceramics with cubic crystal system and space group Ia-3d (230) was determined by XRD and Rietveld refinement. SEM observation confirmed the garnet structure of Lu2MgAl4SiO12 ceramics, and verified the dense structure of the ceramic samples with a relative density of 99.1%. In addition, the influence of relative density and packing fraction on Q x f was studied by analyzing the Lu2MgAl4SiO12 system. The findings revealed that tau f was affected by the valence state of VSi-O bond. Finally, Lu2MgAl4SiO12 sample sintered at 1490 degrees C demonstrated notable microwave properties (epsilon r = 9.13, Q x f = 15,100 GHz, tau f = -47.1 ppm/degrees C).