Low-temperature sintering and microwave dielectric properties of CaSnxSiO(3+2x)-based positive τf compensator

Abstract The sinterability, phase compositions, and microwave dielectric properties of LiF-doped nonstoichiometric CaSn x SiO (3+2 x ) ceramics prepared by the solid-state reaction were investigated. LiF addition effectively reduced the sintering temperature of CaSn x SiO (3+2 x ) ceramics and inhibited the volatilization of Sn. A pure monoclinic CaSnSiO 5 phase was achieved in the 1.0 wt% LiF-doped CaSn 0.94 SiO 4.88 ceramics sintered at 1175 °C, which exhibited good microwave dielectric properties of e r = 11.6, Q × f  = 34000 GHz, and τ f = +73.2 ppm/°C. The positive τ f value was an atypical and important phenomenon for low-permittivity microwave dielectric ceramics, which could be a promising τ f compensator.