Iron ultrafine nanoparticles prepared by aerosol laser pyrolysis

alpha-Fe nanoparticles have been prepared by a continuous process based on the CO2 laser-induced pyrolysis of an iron pentacarbonyl aerosol. Uniform spherical nanoparticles of diameters between 13 and 24 nm consisting of an iron core and an oxide layer were obtained by this technique. It has been found that the mean particle size and the proportion of iron oxide vary with the laser power. Structural characteristics of the samples were determined by TEM and X-ray diffraction (XRD). Size distributions, determined both from TEM measurements and from X-ray diffraction by fitting the Fe(110) diffraction peak profile, are compared and discussed. Finally, the magnetic characterisation of the iron powders was carried out by attending to the hysteresis loop characteristics at room temperature. (C) 2002 Elsevier Science B.V. All rights reserved.