Impedance spectroscopy of perovskite barium substituted lead zinc niobate ceramics

The complex perovskite lead barium zinc niobate, (Pb1−xBax)(Zn1/3Nb2/3)O3 ceramic at x=0.25 was prepared by a columbite precursor method. The microstructure analysis was done by scanning electron microscope. The field dependences of the dielectric response and the conductivity were measured in a frequency range from 100 Hz to 1 MHz and in a temperature range from 110 to 310 K. The frequency dependence of the loss peak is found to obey Arrhenius law with activation energy of ∼0.019 eV. An analysis of the real and imaginary parts of the dielectric permittivity with frequency has been performed, assuming a distribution of relaxation times as confirmed by Cole–Cole plot. The frequency dependent electrical data were also analyzed in the framework of the conductivity and modulus formalism. Both these formalisms provided qualitative similarities in the relaxation times.