Preparation And Characterization Of Fe₃O₄Nanoparticles

Compared with the corresponding bulk materials, nano-sized magnetic particleshave different physical and chemical characteristics. People carried out extensive andin-depth study on these characteristics. Due to their surface effect, superparamagnetism,biocompatibility, Fe₃O₄nanoparticles have a wide application in magnetic storagematerials, magnetic fluids, catalysis, biomedicine materials and radar absorbing materials,etc. The properties of Fe₃O₄nanoparticles depend strongly on their dimensions. Uniformsize make each particle has same physical and chemical properties. Therefore, thepreparation of Fe₃O₄nanoparticles with uniform size and morphology has importantsignificance. In this paper, corprecipitaion and solvothermal method were used tosynthesis Fe₃O₄nanoparticles. Fe₃O₄nanoparticles were synthesized by the thermaldecomposition of FeOOH with oleic acid as surfactant and1-octadecene as solvent. Thetransmission electron microscopy （TEM）, X-ray powder diffraction （XRD）, andmagnetization measurement were used to characterize the morphology, structure, andmagnetic properties of the as-prepared nanoparticles. The influence of oleic acid andFeCl3content, reaction time on the size, morphology and magnetic properties of Fe₃O₄nanocrystals were studied. The results demonstrate that both the prolonging of reactionduration and the increasing of FeCl3content can increase the diameter of magnetiteparticles. By increase the oleic acid from13.5ml to20ml, the particle diameter firstdecrease and then increase. Monodisperse Fe₃O₄nanoparticles with uniform size werealso prepared by coprecipitation methods with oleic acid as surfactant and aging at180℃for16h.