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 Lu 2 MgAl 4 SiO 12 microwave dielectric ceramic was prepared by traditional solid-phase method. The successful synthesis of Lu 2 MgAl 4 SiO 12 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 Lu 2 MgAl 4 SiO 12 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  ×  f was studied by analyzing the Lu 2 MgAl 4 SiO 12 system. The findings revealed that τ f was affected by the valence state of V Si-O bond. Finally, Lu 2 MgAl 4 SiO 12 sample sintered at 1490 °C demonstrated notable microwave properties ( ε r  = 9.13, Q  ×  f  = 15,100 GHz, τ f  = –47.1 ppm/°C).