MICROWAVE DIELECTRIC-PROPERTIES AND SINTERING OF BA6-3X R8+2XTI18O54 (R = SM, X = 2 3) SOLID-SOLUTION WITH ADDED RUTILE/

The tungsten bronze-type Ba6-3xR8+2xTi18O54 solid solutions are known to be applicable as microwave dielectric ceramic resonators with high epsilon(r). The sintering temperature of these solid solutions is as h igh as 1460 degrees C because they are congruent melting compounds. Th erefore, in order to decrease the sintering temperature, we considered a composite with eutectic point, which is composed of the solid solut ion and rutile. We successfully decreased the sintering temperature an d adjusted the temperature coefficient of the resonant frequency (tau( f)) to zero by adding rutile with high tau(f). The composite with Ba4S m9.33Ti18O54.1.4TiO(2) sintered at 1350 degrees C has excellent microw ave dielectric properties such as tau(f) = 0 ppm/degrees C, epsilon(r) = 81.5 and Q . f = 10,414 GHz.