Microwave dielectric properties of Ba(6-3x)Pr(8+2x)Ti18O54 ceramics

Ceramics in the solid solution of Ba(6-3x)Pr(8+2x)Ti18O54 have been prepared by the mixed oxide route. Single phase ceramics were obtained in the range of 0 <x <0.75. The microstructure of these ceramics are composed of needle-like grains in the range of 1-10 microns; the aspect ratio of the grains increased with the increasing x. Higher temperatures were required to obtain high density ceramics at compositions with higher x value. The microwave dielectric properties of the Ba(6-3x)Pr(8+2x)Ti18O54 strongly depends on the x value. The relationship between microstructures and dielectric properties are reported. Ceramics with x=0.5 were also prepared by a chemical route; the properties were k=91, Q=1600 at 4GHz and tau (f) of 160 ppm/degreesC.