Microwave dielectric properties and infrared reflectivity spectra analysis of two novel low-firing AgCa2B2V3O12 (B = Mg, Zn) ceramics with garnet structure

Two Ag-containing microwave dielectric ceramics AgCa2B2V3O12 (B = Mg, Zn) with garnet structure were prepared through solid-state reaction method. Dense ceramics were obtained at low sintering temperatures, 665 °C for AgCa2Zn2V3O12 and 730 °C for AgCa2Mg2V3O12. Their microwave dielectric properties were characterized for the first time and analyzed by means of packing fraction, bond valence, octahedral distortion, Raman spectra and infrared reflectivity spectra. Both compounds displayed high chemical compatibility with Ag electrodes. Additionally, thermally stable ceramics with near-zero temperature coefficients of resonance frequency (τf) were achieved by forming ceramic composites with CaTiO3.