Low-temperature sintering and microwave dielectric properties of LiF-doped 0.2Li2ZrO3–0.8MgO ceramics

The 0.2Li2ZrO3–0.8MgO (Li2Mg4ZrO7) ceramics were prepared by conventional solid-state reaction method. The effects of lithium fluoride (LiF) addition on the microstructure, sintering temperature and microwave dielectric properties of Li2Mg4ZrO7 ceramics were investigated. The experimental results demonstrated a typical single phase existed in Li2Mg4ZrO7–LiF ceramics, in which LiF was proved to be an effective sintering aid for the Li2Mg4ZrO7 ceramic. LiF obviously lowed the optimum sintering temperature of Li2Mg4ZrO7 ceramic from 1500 to 1050 °C and improved the sintering ability of the matrix. In this paper, the microwave dielectric properties were strongly dependent on the amount of LiF additions and the sintering temperature. Optimum microwave dielectric properties (εr = 12.95, Q·f = 180,011 GHz and τf =− 23.51 ppm/°C) were obtained in Li2Mg4ZrO7-4 wt% LiF ceramics sintered at 1050 °C.