Affordable Access

Publisher Website

AC conductivity and dielectric relaxation in Ba(Sm1/2Nb1/2)O3ceramic

Authors
Journal
Physica B Condensed Matter
0921-4526
Publisher
Elsevier
Publication Date
Volume
406
Issue
2
Identifiers
DOI: 10.1016/j.physb.2010.09.019
Keywords
  • Perovskite
  • X-Ray Diffraction
  • Dielectric Constant

Abstract

Abstract The complex perovskite oxide a barium samarium niobate (BSN) synthesized by solid-state reaction technique has single phase with cubic structure. The scanning electron micrograph of the sample shows the average grain size of BSN∼1.22 μm. The field dependence of dielectric response and loss tangent were measured in the temperature range from 323 to 463 K and in the frequency range from 50 Hz to 1 MHz. The complex plane impedance plots show the grain boundary contribution for higher value of dielectric constant in the low frequency region. An analysis of the dielectric constant ( ε′) and loss tangent (tan δ) with frequency was performed assuming a distribution of relaxation times as confirmed by the scaling behaviour of electric modulus spectra. The low frequency dielectric dispersion corresponds to DC conductivity. The logarithmic angular frequency dependence of the loss peak is found to obey the Arrhenius law with an activation energy of 0.71 eV. The frequency dependence of electrical data is also analyzed in the framework of conductivity and electric modulus formalisms. Both these formalisms show qualitative similarities in relaxation times. The scaling behaviour of imaginary part of electric modulus M″ and dielectric loss spectra suggest that the relaxation describes the same mechanism at various temperatures in BSN. All the observations indicate the polydispersive relaxation in BSN.

There are no comments yet on this publication. Be the first to share your thoughts.