Microwave dielectric properties of low-fired Li2ZrO3–ZnO composite ceramics

We fabricated the low-fired (1 − x)Li2ZrO3–xZnO (0.1 ≤ x ≤ 0.5) composite ceramics doped with 3 wt% LiF by a conventional solid-state route, and investigated systematically their sintering characteristics, microstructures and microwave dielectric properties. The results showed that Li2ZrO3 and ZnO coexist in the sintered ceramics, and temperature stability of Li2ZrO3 ceramics were improved by doping ZnO. Furthermore, addition of LiF successfully reduced the sintering temperatures of Li2ZrO3–ZnO ceramics to below 950 °C. A typical sample of 0.7Li2ZrO3–0.3ZnO–3 wt% LiF with optimum dielectric properties (ɛr = 14.8, Q × f = 26,800 GHz, τf = 1 ppm/°C) were achieved at 940 °C for 4 h. Such sample was compatible with Ag electrodes, suitable for the low-temperature co-fired ceramics (LTCC) applications.