Low-temperature sintering and microwave dielectric properties of Li4Mg3Ti2O9 ceramics by a sol–gel method

Abstract

The pure phase Li4Mg3Ti2O9 with nanopowders of 37 nm was prepared by a sol–gel method and calcinated at 600, 450 °C lower than that by a conventional solid-stated method. The sintering temperature of Li4Mg3Ti2O9 with addition of LiF (≥ 2 wt%) was reduced from 1275 to 800 °C with enhancement of density and microwave dielectric properties, related to the substitution of F− ion for O2− ion in Li4Mg3Ti2O9 compound at low temperature. Addition of LiF broadened the sintering window (800–1000 °C). The Li4Mg3Ti2O9–4 wt% LiF ceramic sintered at 850 °C exhibited good microwave dielectric properties of er = 17.5, Q × f = 89,320 GHz (at 9.1 GHz), and τf = − 37.4 ppm/°C. Such samples were compatible with Ag electrodes, promising to be a candidate material for low-temperature co-fired ceramics technology application.