Effect of microwave sintering on the microstructure and dielectric properties of 0.92MgAl₂O₄–0.08(Ca_0.8Sr_0.2)TiO₃ ceramics

The 0.92MgAl₂O₄–0.08(Ca_0.8Sr_0.2)TiO₃ ceramics were fabricated using microwave and conventional sintering techniques. The effects of microwave sintering and conventional sintering on the sintering behaviour, microstructure and microwave dielectric properties of 0.92MgAl₂O₄–0.08(Ca_0.8Sr_0.2)TiO₃ ceramics were investigated. The sintering time of microwave sintering was much shorter and the impurity phase Ca₃Al₂O₆ was eliminated as compared with conventional sintering. Furthermore, the microwave sintering samples exhibited higher densification, more uniform grain distribution and better dielectric properties. As a result, excellent dielectric properties of 11.20 for ε_r, 56217 GHz for Q × f, and −3.4 ppm/ °C for τ_f were obtained by microwave sintering at 1440 °C for 20 min.