Effect of nickel substitutions on some properties of Cu-Zn ferrites

The spinet ferrite system Cu(0.8) (x)Zn(0.2)Ni(x)Fe(2)O(4); 0.0 <= x <= 0.8 is prepared by standard ceramic method. X-ray diffraction (XRD) measurements, are used for analyzing the composition, lattice parameter, density, porosity and grain size of these compounds. The infrared spectra (IR) obtained ill room temperature in the range 400-4000 cm (1) showed two absorption spectra. The high-frequency band (nu(1)) and low-frequency band (nu(2)) are assigned to the tetrahedral and octahedral complexes, respectively. The electrical measurements of these ferrites at various compositions were investigated from room tempertature up to 650 K in the frequency range (10(2)-10(5) Hz). The obtained results revealed semiconductor behavior with,in increasing nickel concentration with change in the slope at transition temperature T(c). The determined T(c) is found to increase with an increasing Ni concentration. The activation energies calculated at the magnetic region are found to decrease with an increasing Ni content. The relation of the universal exponent s With temperature gives evidence for file presence of the large overlap polaron (LOP) hopping conduction mechanism in these. compounds. The obtained results of conductivity are explained in light of the hopping conduction occurring at the octahedral B-Sites. (c) 2008 Elsevier B.V. All rights reserved.