A novel preparation method for γ-Fe2O3 nanoparticles and their characterization

In this paper, γ-Fe2O3 nanoparticles have been prepared by treating the hydroxide precursor in FeCl2 solution. A new transition process induced chemically for preparing oxide nanoparticles is revealed by energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy. The precursor, consisting of a mixture of FeOOH and Mg(OH)2, was synthesized using a common co-precipitation method. After treatment by boiling in FeCl2 solution, γ-Fe2O3 nanoparticles, about 10 nm diameter, were formed. The nanoparticles are highly crystalline and the specific saturation magnetization σs reaches 69.20 emu g−1, which is 90 percent of the value for bulk γ-Fe2O3 and is higher than the value for γ-Fe2O3 nanoparticles of the same size prepared by other methods. The nanoparticles have an inert FeCl2 surface, giving them relatively good chemical stability and dispersivity.