Effect of LiF addition on the sinterability, crystal structure and microwave dielectric properties of Li3Mg4NbO8 ceramics

The normative solid-state reaction process was adopted to prepare Li3Mg4NbO8 ceramics with LiF addition. We investigated the impacts of LiF additive on the crystal structure, sinterabiffity as well as dielectric performance at microwave region of the Li3Mg4NbO8 -basic ceramics. XRD analysis confirmed that the addition of LiF to Li3Mg4NbO8 lead to the formation of new phase Li3Mg4NbO8F with cubic rock salt structure. The densified temperature of Li3Mg4NbO8-basic ceramics could be effectively reduced from 1150 degrees C to 900 degrees C with LiF addition. Both the permitivity (epsilon(r)) and quality factor (Qf) of present ceramics were is closely correlated with the bulk density and cell volume. The 900 degrees C-sintered Li3Mg4NbO8 -basic ceramics owned excellent chemical compatibility with silver and optimized microwave dielectric performance (epsilon(r) similar to 13. 4, Qf similar to 32,400 GHz at 9.4 GHz, and temperature coefficient of resonant frequency (tau(f)) similar to -43.0 ppm/degrees C).