Electrical characterization and equivalent circuit analysis of (Bi1.5Zn0.5)(Nb0.5Ti1.5)O7 Pyrochlore, a relaxor ceramic

Abstract

The ac impedance of (Bi1.5Zn0.5)(Nb0.5Ti1.5)O7, a relaxor ceramic with the pyrochlore structure, has been measured over the temperature range 10–1073K and analyzed using a combination of traditional, fixed-frequency sweeps of permittivity and tan d, impedance analysis using resistancecapacitance (RC) circuit combinations and equivalent circuit modeling with the inclusion of a constant phase element (CPE). Low temperature data accurately fit an equivalent circuit containing a parallel R-C-CPE element in series with a capacitor. From the temperature-dependence of the fitted R,C,CPE parameters, a model for the relaxor behavior is obtained.