MICROWAVE DIELECTRIC PROPERTIES OF Nb2O3-Zn0.95Mg0.05TiO3+0.25TiO2 CERAMICS WITH Bi2O3 ADDITION

In this study, the effects of Bi2O3 addition of up to 10 wt% on sintering characteristics, microwave dielectric properties and microstructures of Nb2O3-Zn0.95Mg0.05TiO3 + 0.25TiO(2) + 0.25TiO(2) (Nb-ZMT') ceramics, prepared by conventional solid-state routes have been investigated. The sintered ceramic samples were characterized by X-ray diffraction and scanning electron microscopy (SEM). It was found that as the content of Bi2O3 increased, the density of the sintered ceramics increased, and the density of Nb-doped samples with 5 wt% Bi2O3 was over 98% of theoretical density. The dielectric constant of the Nb-doped samples increased with increasing Bi2O3 content. In addition, Cr of the Nb-doped samples was higher than the undoped samples. The Nb-ZMT' ceramic with 5 wt% Bi2O3 addition sintered at 900 degrees C exhibited the optimum dielectric properties: Qxf = 12000 GHz, epsilon(r) = 30, and tau f = -12 ppm / degrees C.