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

Abstract

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 τf value was obtained at 1325°C for Li2SnO3-8wt% MgO ceramics. Furthermore, LiF addition not only successfully lowered the sintering temperatures to 880°C but also promoted formation of Li2Mg3SnO6. The microwave dielectric properties of Li2SnO3-8wt% MgO ceramics were further optimized with increasing Li2Mg3SnO6 content. The excellent microwave dielectric properties (εr=14.7, Q×f=78,400GHz, and τf=−0.9ppm/°C) were achieved at 880°C for Li2SnO3-8wt% MgO-2wt% LiF ceramics, which is compatible with Ag electrodes and suitable for the low-temperature co-fired ceramics (LTCC) applications.