Dielectric relaxation in complex perovskite BaFe1/2Sb1/2O3

Abstract

The complex perovskite oxide barium iron antimonate, BaFe 1/2Sb1/2O3 (BFS) is synthesized by a solid-state reaction technique for the first time. The X-ray diffraction of the sample at room temperature shows a monoclinic phase. The field dependences of dielectric response and the loss tangent of the sample are measured in a frequency range from 50 Hz to 1 MHz and in a temperature range from 143 to 463 K. An analysis of the loss factor with frequency is performed by the scaling behavior of the dielectric loss spectra. The frequency dependence of the loss peaks are found to obey the Arrhenius law with an activation energy ≃0.81 eV. The scaling behavior of the dielectric loss spectra suggests that the distribution of relaxation times is temperature-independent. The frequency-dependent electrical data are also analyzed in the framework of conductivity and electric modulus formalisms. The scaling behavior of the imaginary electric modulus shows the temperature-independent nature of the distribution of relaxation times. All these formalisms resulted in the qualitative similarities in the relaxation time. The relar tionship between relaxation parameters and electrical conduction indicates the hopping motion of electrons from Fe(II) to Fe(III) ions in BFS.