Structural and electrical features of rare earth based double perovskite oxide: Pr2NiZrO6

Abstract

Dielectric relaxation measurements are carried out on Pr2NiZrO6 (PNZ) sample at several frequencies between temperature 313 K and 593 K. The powder was analyzed by X-ray powder diffraction (XRD). Rietveld analysis identified a highly crystalline double perovskite phase. However, a secondary pyrochlore phase, Pr2Zr2O7, was also detected. The dielectric spectrum shows several relaxation processes in increasing order of temperature. Detailed studies of dielectric and impedance parameters as a function of temperature and frequency have shown the significant effect of grains and grain boundaries in the relaxation process. Dielectric loss spectra reveal that dc conduction contribution predominates in the compound. Imaginary part of electric modulus (M″) exhibit two sets of apparent peaks corresponding to the relaxed dipole and to the conductive process. The scaling analyses reveal different temperature dependence of conductivity for PNZ. The temperature dependent conductivity was conformed from the Arrhenius relation and the activation energy is found to be 0.357 eV.