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 Mg1-xCoxSiO3 (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(u)f(o) value of MgSiO3 was enhanced from 103,453 to 145,846GHz 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 degrees 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 compositionswith x>0. Good dielectric properties at microwave frequencies i.e. epsilon(r)8.11, Q(u)f(o) 145,846GHz and (f) -12ppm/degrees C wereobtained for the composition with x=0.15 sintered at 1350 degrees C for 9h. This is suggested to be a very favorable dielectric material for millimeterwave applications.