Understanding the effect of high energy γ-radiation induced on the structural and electrical behavior of Eu3+-substituted Mg–Cd nanoferrites

Abstract

The nano-sized Mg1−xCdxEuyFe2−yO4 (0.0 ≤ x ≤ 1.0; y = 0.0, 0.1) ferrites are synthesized by combustion technique. All samples are subjected to γ-radiation of 60Co source with overall 310 kGy exposure dosage. The structural analysis of all the samples is done using XRD. The structural parameters of Mg–Cd–Eu nanoferrites before and after irradiation are estimated by applying Rietveld refinement to XRD data. Furthermore, the lattice parameters are found to be increasing with increase in Cd2+ ion content. The average crystallite sizes are found in the range of 12–38 nm. The morphology of the samples before and after gamma irradiations was observed by using SEM. The morphology of the samples confirms the porous nature after gamma irradiation and EDAX analysis confirms the composition details of the samples. XPS analysis of the samples confirms the oxidation state of all the elements. Dielectric constant, dielectric loss tangent, complex impedance, and AC conductivity properties are measured in the frequency range of 100 Hz–5 MHz at room temperature before and after gamma irradiation. The dielectric constants, dielectric loss tangent, and impedance increased with increasing concentration of Cd2+. The ac conductivity decreased with the increase in Cd2+ concentration. The dielectric constant and lattice parameter values have essentially decreased with substitution of Eu3+ ion and enhanced after gamma illumination because of the change of ferric particles into ferrous particles due to the ionizing impact of γ-illumination. The Cole–Cole plots reveal the existence of various electrical responses in the samples. Hence our results suggest that these materials are helpful for radio frequency application.