Electrical properties of Ba2YbNbO6: an impedance spectroscopy study

The electrical properties of a rare-earth based double perovskite oxide barium ytterbium niobate, Ba2YbNbO6 (BYN), synthesized by the solid-state reaction technique are investigated. The Rietveld refinement of the x-ray diffraction pattern suggests that the compound has a cubic phase at room temperature with a Fm3m space group. The room temperature Raman spectrum also supports the cubic crystal structure of BYN. The frequency-dependent dielectric dispersion of the material is investigated in the temperature range from 303 to 603 K. The Cole-Cole model is used to analyze the dielectric relaxation phenomenon. The complex impedance data are analyzed by an electrical equivalent circuit consisting of a resistance and a constant phase element in parallel, where the ideal capacitance part is replaced by a constant phase element. The frequency dependent conductivity spectra follow the double power law. The scaling behavior of the imaginary part of the dielectric constant (epsilon '') suggests that relaxation describes the same mechanism at various temperatures in BYN.