Microwave-induced polyol-process synthesis of MIIFe2O4 (M = Mn, Co) nanoparticles and magnetic property

(MFe2O4)-Fe-II (M = Mn, Co) nanoparticles with diameters less than 10 nm were prepared by a fast and simple microwave-assisted method using ethylene glycol (EG) and ferric salts as starting reagents. The use of microwave field during preparation dramatically enhanced the crystallization rate. Therefore, well-crystallized MnFe2O4 and CoFe2O4 nanoparticles were prepared under microwave heating for 10 min without calcining steps. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). In addition, both MnFe2O4 and CoFe2O4 nanoparticles exhibit a small hysteresis loop at room temperature. (C) 2007 Elsevier B.V. All rights reserved.