Dielectric and complex impedance properties of γ-rays irradiated Neodymium substituted Co-Zn nanoferrites

Abstract

Nanosized Co1−xZnxFe2−yNdyO4 ferrites with x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0.0 and 0.1 were synthesized by solution combustion method. All the compositions have been characterized by XRD, SEM technique and irradiated by γ–rays of 60Co source. Dielectric constant, dielectric loss tangent, ac conductivity and complex impedance are studied in the frequency range 100kHz–10MHz for pristine and irradiated composition. The X-ray diffraction patterns revealed the spinel cubic structure. The lattice parameter has increased with increasing Zn2+ ion concentration. The values of dielectric constant, loss tangent, real and imaginary parts of impedance have been decreased while ac conductivity increased with increasing frequency. The dielectric parameters and ac conductivity were found to increase and attain maximum at x=0.4; y=0.0, x=0.6; y=0.10 and beyond that decreased for further substitution of Zn2+ ion concentration. The lattice parameter and dielectric parameters were significantly reduced with Nd3+ ion substitution and increased after γ-irradiation attributed to the conversion of ferric ions to ferrous due to ionizing effect of γ-radiation. Nyquist plots revealed existence of multiple electrical responses.