Densification, microstructural evolution, and dielectric properties of CaTiO3–LaGaO3 microwave ceramics

The relations among the densification, microstructural evolution, and microwave dielectric properties of the (1−x)CaTiO3–xLaGaO3 ceramics with x=0.34 and 0.36 were investigated in this study. The results indicated that (1−x)CaTiO3−xLaGaO3 ceramics can be densified at 1300 °C with at least 97% of the theoretical value. The ceramics reported an orthorhombic perovskite structure, and no other detectable phases were found. Both εr and Q×f values can be improved by slowing the cooling rate during sintering. The εr and Q×f values of the 0.64CaTiO3–0.36LaGaO3 ceramics at cooling rates of >10 °C/min and 0.1 °C/min are 48.1 and 27,500 and 48.7 and 38,000, respectively. The higher densification obtained at a slower cooling rate plays an important role in improving the microwave dielectric properties.

► Cooling rate is important for improving the microwave properties of CaTiO3–LaGaO3 ceramics.
► CaTiO3–LaGaO3 ceramics densified at 1300 °C, with at least 97% theoretical density.
► εr and Q×f of 0.64CaTiO3–0.36LaGaO3 ceramic are 48.7 and 38,000 for cooling rate of 0.1°C/min.