Ultra-low temperature sintering and temperature stable microwave dielectrics of phase pure AgMgVO4 ceramics.

The present study systematically invesitgates the formation and microwave dielectric properties of novel AgMgVO 4 ceramics fabricated via the solid-state reaction method. The crystal structure of the ceramics is confirmed to be orthorhombic with a space Group of Pnma (62). A high relative density of 96.2% and an excellent combination of microwave dielectric properties with ε r of ~14.89, Q × f of ~19,400 GHz, and τ f of ~ − 2.71 ppm/°C can be achieved for the ceramic sintered at 630 °C. The dielectric constant is mainly influenced by the relative density (porosity) and dielectric polarizability. The Q × f is controlled by the microstructure, packing fraction, and lattice energy, which are also highly related to the unit-cell volume. A smaller unit-cell volume leads to a high Q × f. Variation of the τ f is strongly correlated to the bond valence of the specimen. Furthermore, the ceramic exhibits good chemical compatibility with aluminum electrodes and is demonstrated as a potent substrate for a band-pass filter with a center frequency of 3.5 GHz. These findings show a great promise for ultra-low temperature co-fired ceramic applications at high frequencies. [ABSTRACT FROM AUTHOR]