Effect of preparative conditions on magnetic properties of CoFe 2O4 nanoparticles

Nanomagnetic particles of CoFe<inf>2</inf>O<inf>4</inf> have been synthesized using chemical co-precipitation technique followed by annealing, characterized and investigated by powder XRD and magnetic measurement tools. All samples of nano ferrites synthesized at different annealing temperatures show single phase cubic spinel structure with particle size changes from 9.5 to 21 nm. The virgin curve of magnetic measurement exhibits superparamagnetic behaviour at room temperature which changes to 'S' shape with increasing annealing temperature indicating change in soft magnet to pinning-type magnet. The coercivity of the nano-cobalt ferrite particles has been found to increase with increase in annealing temperature.