Sintering Behaviors, Microstructure, and Microwave Dielectric Properties of CaTiO3-LaAlO3 Ceramics Using CuO/B2O3 Additions

The effect of CuO/B2O3 additions on the sintering behaviors, microstructures, and microwave dielectric properties of 0.95LaAlO(3)-0.05CaTiO(3) ceramics is investigated. It is found that the sintering temperatures are lowered efficiently from 1600 degrees C to 1350 degrees C, as 1 wt % CuO, 1 wt % B2O3, and 0.5 wt % CuO +0.5 wt % B2O3 are used as the sintering aids due to the appearance of the liquid phase sintering. The microwave dielectric properties of 0.95LaAlO(3)-0.05CaTiO(3) ceramics with the sintering aid additions are strongly related to the densification and the microstructure of the sintered ceramics. At the sintering temperature of 1300 degrees C, the 0.95LaAlO(3)-0.05CaTiO(3) ceramic with 0.5 wt % CuO + 0.5 wt % B2O3 addition shows the best dielectric properties, including a dielectric constant (epsilon(r)) of 21, approximate quality factor (Q x f) of 22,500 GHz, and a temperature coefficient of the resonant frequency (tau(f)) of -3 ppm/degrees C.