Microwave dielectric characteristics of Li2(Mg0.94M0.06)Ti3O8 (M=Zn, Co, and Mn) ceramics

Li2(Mg0.94M0.06)Ti3O8 (M=Zn, Co, and Mn) ceramics were synthesized by the conventional solid-state reaction route. The effect of M (Zn, Co, and Mn) substitution on the structure, microstructure and microwave dielectric properties of Li2(Mg0.94M0.06)Ti3O8 has been investigated. The XRD patterns of sintered samples revealed the single-phase formation with spinel structure. With the increase in ionic radius of M, the Qf value decrease is attributed to the decrease of packing fraction and grain size. The Li2(Mg0.94Zn0.06)Ti3O8 ceramic sintered at 1075 °C for 4 h showed the best microwave dielectric properties with a dielectric constant of 27.1, a Qf value of 44 800 GHz, and a temperature coefficient of resonant frequency of (+)1.9 ppm/°C.