Synthesis and Microwave Dielectric Properties of MgSiO ₃ Ceramics

MgSiO 3 ceramics were synthesized and their microwave dielectric properties were investigated. The Mg 2 SiO 4 phase was formed at temperatures lower than 1200°C, while the orthorhombic MgSiO 3 phase started to form by the reaction of SiO 2 and Mg 2 SiO 4 in the specimen fired at 1200°C. The structure of the MgSiO 3 ceramics was transformed from orthorhombic to monoclinic when the sintering temperature exceeded 1400°C. A dense microstructure was developed for the specimens sintered at above 1350°C. The excellent microwave dielectric properties of ɛ r =6.7, Q × f =121 200 GHz, and τ f =−17 ppm/°C were obtained from the MgSiO 3 ceramics sintered at 1380°C for 13 h.