Microwave dielectric properties of novel temperature stable high Q Li2Mg1−xZnxTi3O8 and Li2A1−xCaxTi3O8 (A = Mg, Zn) ceramics

The Li2Mg1−xZnxTi3O8 (x = 0–1) and Li2A1−xCaxTi3O8 (A = Mg, Zn and x = 0–0.2) ceramics are synthesized by solid-state ceramic route and the microwave dielectric properties are investigated. The Li2MgTi3O8 ceramic shows ɛr = 27.2, Qu × f = 42,000 GHz, and τf = (+)3.2 ppm/°C and Li2ZnTi3O8 has ɛr = 25.6, Qu × f = 72,000 GHz, and τf = (−)11.2 ppm/°C respectively when sintered at 1075 °C/4 h. The Li2Mg0.9Zn0.1Ti3O8 dielectric ceramic composition shows the best dielectric properties with ɛr = 27, Qu × f = 62,000 GHz, and τf = (+)1.1 ppm/°C. The effect of Ca substitution on the structure, microstructure and microwave dielectric properties of Li2A1−xCaxTi3O8 (A = Mg, Zn and x = 0–0.2) has also been investigated. The materials reported in this paper are excellent in terms of dielectric properties and cost of production compared to commercially available high Q dielectric resonators.