Structural, dielectric and electrical properties of Ni (Cd, Zn) Fe2O4 by Auto Combustion method

Nickel ferrite nano-particles having the basic composition Ni0.75M0.25Fe2O4 (M=Cd+2, Zn+2) were prepared using auto combustion method. The structural, dielectric and a.c conductivity of these samples, which were sintered at 900(0)C were studied. The structures of the synthesized samples were probed by X-ray diffraction (XRD) studies. The peaks observed in the XRD spectrum indicated single phase spinel cubic structure for the synthesized samples. Surface morphology of the samples has been investigated using Field Emission Scanning Electron Microscope (FESEM). The dielectric constant (epsilon') and dielectric loss tangent (tan delta) of doped nano-crystalline nickel ferrites were investigated as a function of frequency at room temperature over the frequency range 100 Hz to 1 MHz using Hioki make LCR Hi-Tester 3250. Dielectric dispersion was observed for the synthesized samples. The dependence of epsilon' and tan delta with the frequency of the alternating applied electric field is in accordance with the Maxwell-Wagner type interfacial polarization. The electrical conductivity (sigma(ac)) deduced from the measured dielectric data has been thoroughly analyzed and found that the conduction mechanism in Cd+2 and Zn+2 doped NiFe2O4 nanoferrite are in conformity with the electron hopping model. (C) 2017 Elsevier Ltd. All rights reserved.