Microwave dielectric properties of low-fired Li2TiO3-MgO ceramics for LTCC applications

We fabricated the low-fired Li2TiO3-MgO ceramics doped with LiF by a conventional solid-state route, and investigated systematically their sintering characteristics, microstructures and microwave dielectric properties. The results showed that temperature stability of Li2TiO3 ceramics were improved by doping MgO. Well microwave dielectric properties for Li2TiO3-13 wt%MgO (LTM) ceramics with epsilon(r) = 16.4, Qxf = 87,500 GHz, and tau(f) = -1.2 ppm/degrees C were obtained at 1325 degrees C. Furthermore, addition of LiF enhanced the sinterability and optimized the microwave dielectric properties of LTM ceramics. A typically sample of LTM-4wt%LiF ceramics with optimum dielectric properties (epsilon(r) = 15.8, Qxf = 64,500 GHz, and tau(f) = -0.2 ppm/degrees C) were achieved at 850 degrees C for 4 h. Such sample was compatible with Ag electrodes, suitable for the low-temperature co-fired ceramics (LTCC) applications. (C) 2015 Elsevier B.V. All rights reserved.