Microwave dielectric properties and microstructure of 0.85MgTiO3-0.15Ca0.6La0.8/3TiO3 dielectric ceramics with added sintering aids

The effects of additive sintering aids on the microstructures and microwave dielectric properties of 0.85MgTiO(3)-0.15Ca(0.6)La(0.8/3)TiO(3) ceramics were investigated. CuO was selected as a liquid phase sintering aid to lower the sintering temperature of 0.85MgTiO(3)-0-15Ca(0.6)La(0.8/3)TiO(3) ceramics. With added CuO, the densification temperature of 0.85MgTiO(3)0.15Ca(0.6)La(0.8/3)TiO(3) can be effectively reduced from 1450 to 1160-1300 degrees C. Low-level doping of CuO (0.5-5wt%) significantly improves the density and dielectric properties of 0.85MgTiO(3)-0.15Ca(0.6)La(0.8/3)TiO(3) ceramics. The quality factor Q x f was strongly dependent upon the amount of additives. Q x f values of 60000 and 20000 GHz could be obtained at 1160-1300 degrees C with 0.5 and 5 wt % CuO added, respectively. Over all ranges of addition, the relative dielectric constants differed significantly and ranged from 23.2 to 26.1. The temperature coefficient varied from 0 to -3.7 ppm/degrees C.