Abstract

Hana NACEUR^*, Adel MEGRICHE , Mohamed EL MAAOUI

DOI : http://dx.doi.org/10.13005/ojc/290311

This study reports the frequency effect on the dielectric properties and electrical conductivity of Sr1−x(Na0.5Bi0.5)xBi2Nb2O9 (x = 0.0, 0.2, 0.5, 0.8 and 1.0) ceramics, at various temperatures. A strong low frequency dielectric dispersion was observed in these ceramics. The dielectric constant, the tangent loss and the ac electrical conductivity measured as function of frequency have been found to fit to the Jonscher’s dielectric dispersion relations. Electrical measurements were influenced by two mechanisms, polarization due to the carrier displacement in the low frequency region and the contribution from the lattice at high frequencies. The ac conductivity behavior is due to the hopping of oxygen vacancies. Detailed analysis of impedance spectrum suggested that the electrical properties are strongly frequency dependent.

Ceramics;Sintering;Light scattering;Dielectric Properties

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