Low temperature sintering and microwave dielectric properties of 0.2Ca0.8Sr0.2TiO3–0.8Li0.5Sm0.5TiO3 ceramics with BaCu (B2O5) additive and TiO2 dopant

Abstract Low firing temperature 0.2Ca 0.8 Sr 0.2 TiO 3 –0.8Li 0.5 Sm 0.5 TiO 3 (CST–LST) ceramics by BaCu (B 2 O 5 ) addition and TiO 2 dopant were prepared via the conventional solid-state ceramic route, and the sintering, phase evolution, microstructure, and dielectric properties were investigated. Addition of BaCu (B 2 O 5 ) lowered the firing temperature about 300 °C. The CST–LST ceramics with 5 wt% BaCu(B 2 O 5 ) sintered at 950 °C exhibited single phase perovskite structure, together with the optimum microwave dielectric properties of ϵ r = 66.7, Q × f = 3222 GHz, τ f = −21.3 ppm/°C. Adding TiO 2 improved the microwave properties. Typically, the CST–LST + 5 wt% BaCu(B 2 O 5 ) + 1.5 wt% TiO 2 sintered at 950 °C showed ϵ r = 71.6, Q × f = 3441 GHz, τ f = −10.8 ppm/°C. The high permittivity and low temperatures of the ceramics were ideal for the development of low cost ultra-small dielectric loaded antenna. Compatibility with Ag electrode indicated that this material was suitable for low temperature co-fired ceramics.