Microwave dielectric properties of low-fired Li2SnO3 ceramics co-doped with MgO–LiF

Abstract Low-fired Li 2 SnO 3 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 Li 2 Mg 3 SnO 6 was formed. A near-zero τ f value was obtained at 1325 °C for Li 2 SnO 3 -8 wt% MgO ceramics. Furthermore, LiF addition not only successfully lowered the sintering temperatures to 880 °C but also promoted formation of Li 2 Mg 3 SnO 6 . The microwave dielectric properties of Li 2 SnO 3 -8 wt% MgO ceramics were further optimized with increasing Li 2 Mg 3 SnO 6 content. The excellent microwave dielectric properties ( e r = 14.7, Q × f = 78,400 GHz, and τ f = −0.9 ppm/°C) were achieved at 880 °C for Li 2 SnO 3 -8 wt% MgO-2 wt% LiF ceramics, which is compatible with Ag electrodes and suitable for the low-temperature co-fired ceramics (LTCC) applications.