Structural and Electrical Properties of Cobalt Ferrite Nanoparticles

Cobalt ferrite nano-powders were obtained by sol-gelauto-combustion method using citric acid as a fuel. The metalnitrate to citric acid ratio was taken as 1:3. The as preparedpowder of cobalt ferrite nanoparticles is annealed at 5500C for 4hrs and the same powder was used for characterization andinvestigations of structural and electrical properties.Thestructural characterization of cobalt ferrite nanoparticles weredone by X-ray diffraction technique. Micro-structural andmorphological studies were carried out by scanning electronmicroscope technique and energy dispersive spectrum. Theaverage crystallite size obtained by Scherrer’s formula is of theorder of 34 nm. The grain size and specific surface area of thecobalt ferrite nanoparticles is 34 nm and 55 respectively. Thelattice constant determined from XRD data is in the reportedrange (8.3783 A.U.). The porosity estimated from X- ray densityand bulk density shows large value of the order of 47 %. The D.Celectrical resistivity was investigated from room temperature to850 K using two probe technique. The variation of dc electricalresistivity with temperature is explained in this work.