Structural, electrical and magnetic characterization of Ni-Mg spinel ferrites

Soft Ni-Mg spinel ferrites having general chemical formula Ni1-xMgxFe2O4 (0 <= x <= 1) with increment 0.25 were prepared by the co-precipitation method. The samples were characterized by X-ray diffraction (XRD) technique at room temperature. The analysis of XRD data showed the crystallite size variation within the range 10-13 nm. The electrical and magnetic properties of the synthesized ferrites have been investigated as a function of temperature. The DC electrical resistivity (rho) decreases with increase in temperature exhibiting the semiconductor like behavior. The drift mobility (mu(d)) and activation energy (Delta E) are also reported. The dielectrical properties such as dielectric constant (epsilon') and dielectric loss tangent (tan delta) are investigated as a function of frequency. The Curie temperature (T-c) of the present work was determined from AC magnetic susceptibility (chi) data and observed variation are explained on cations distribution among tetrahedral (A) and octahedral (B) sites. (C) 2009 Elsevier B.V. All rights reserved.