DC thermal arc-plasma preparation of nanometric and stoichiometric spherical magnetite (Fe3O4) powders

The DC thermal arc-plasma route is used successfully for the first time for the preparation of magnetite (Fe3O4) powders. The powder is characterized by X-ray diffraction (XRD), vibrating sample magonetometer (VSM), Mossbauer spectroscopy and transmission electron microscopy (TEM) techniques. The size of particles increases with increasing arc-plasma current. High DC arc-current generates the spherical, stoichiometric Fe3O4 particles with comparable magnetic properties (M(s)similar to88 emu/g). The arc-current and hence the oxidation rate is found to be responsible in controlling the size and stoichiometry of the Fe3O4 particles. (C) 2004 Elsevier B.V. All rights reserved.