Low temperature sintering mechanism for Li2Mg3SnO6 microwave dielectric ceramics

•Low-fired Li2Mg3SnO6 ceramics with high Q were prepared.•LiF-doping lowered sintering temperature of Li2Mg3SnO6 ceramics to 900 °C.•A mechanism for low-temperature sintering is the substitution of F− for O2−.•F− substitution for O2− weakened oxygen bond strength and facilitated the diffusion process.•Ceramics with well dielectric properties are suitable for LTCC applications. Low-fired Li2Mg3SnO6 ceramics were fabricated via the conventional solid-state reaction route, and the effects of LiF-doping on their sintering mechanism and microwave dielectric properties were investigated. Sintering temperature of Li2Mg3SnO6 ceramics were effectively reduced to 900 °C due to the substitution of F− for O2−, which could cause weakening of oxygen bond strength induced reduced the intrinsic sintering temperature and facilitates the diffusion process. Low-fired ceramics inhibited volatilization of Li and improved relative density. Well-densified Li2Mg3SnO6-4 wt% LiF ceramics were obtained with optimum microwave dielectric properties of εr = 12.3, Q × f = 96280 GHz and τf = −40.7 ppm/°C at 900 °C. Such samples were compatible with Ag electrodes and suitable for LTCC applications.