Low-fired Li2SnO3 ceramics co-doped with MgO-LiF were fabricated by a conventional solid-state route, and their sinterability, microwave dielectric properties were investigated. With increasing MgO content, a novel phase Li2Mg3SnO6 was formed. A near-zero tau(f) value was obtained at 1325 degrees C for Li2SnO3-8 wt% MgO ceramics. Furthermore, LiF addition not only successfully lowered the sintering temperatures to 880 degrees C but also promoted formation of Li2Mg3SnO6. The microwave dielectric properties of Li2SnO3-8 wt% MgO ceramics were further optimized with increasing Li2Mg3SnO6 content. The excellent microwave dielectric properties (epsilon(r) = 14.7, Q x f = 78,400 GHz, and tau(r) = -0.9 ppm/degrees C) were achieved at 880 degrees C for Li2SnO3-8 wt% MgO-2 wt% LiF ceramics, which is compatible with Ag electrodes and suitable for the low-temperature co-fired ceramics (LTCC) applications. (C) 2016 Elsevier Ltd. All rights reserved.