Control of the Size of Cobalt Ferrite Nanoparticles : Synthesis and Properties

The preparation of a fluid of cobalt ferrite particles having a size varying from 2 to 5nm is described. This has been achieved by using functionalized surfactants. The size of cobalt ferrite particles decreases when the total reactant concentration decreases. The magnetic properties are described with magnetization curves and 57Fe mössbauer spectroscopy. It is demonstrated that these particles are characterized by a superparamagnetic behavior