Influence of Co substitution on the phase, microstructure, and microwave dielectric properties of MgSiO3 ceramics.

Solid-state sintering method was used for the synthesis of Mg_1−xCo_xSiO₃ (x = 0–0.25) ceramics. Phase, microstructure and microwave dielectric properties of the ceramics were investigated. With increase in Co²⁺ content, the increase was observed in the lattice parameters. The Q_uf_o value of MgSiO₃ was enhanced from 103,453 to 145,846 GHz with increasing the value of x content from 0 to 0.15. The Co²⁺ substitution also led to an obvious decrease in the sintering temperature by ~ 100 °C. Clino-enstatite phase formed for the composition with x = 0 while Proto-enstatite formed as the major along with minor clino-enstatite phase for the compositions with x > 0. Good dielectric properties at microwave frequencies i.e. ε_r ~ 8.11, Q_uf_o ~ 145,846 GHz and τ_f ~ − 12 ppm/°C were obtained for the composition with x = 0.15 sintered at 1350 °C for 9 h. This is suggested to be a very favorable dielectric material for millimeterwave applications. [ABSTRACT FROM AUTHOR]