Structure and dielectric properties of pyrochlore-fluorite biphase ceramics in the Bi_3O_3-ZnO-Nb_2O_5 system

摘要

The structure and dielectric properties of Bi_2O_3-ZnO-Nb_2O_5-based ceramics with pyrochlore-fluorite biphase structure were investigated. Mixed-sintered ceramics were prepared by two precalcined constituents in the system of x[Bi_1.5Zn_0.5Nb_1.5]O_7]- (1-x)Bi_1/3Nb_1/4O_7/4 is a defect cubic fluorite (F). The phase composition of the mixed-sintered ceramics were characterized as a biphasic structure with a distorted pyrochlore (β) and a fluorite (F) coexisting. The phase ratio of β pyrochlore and F fluorite is related to the chemical composition x. The dielectric properties of the ceramics gradually change with their structure.