Structural evolution of Fe+Fe2O3 during mechanical milling

The evolution of structure during the mechanical milling of the Fe + Fe2O3 mixture has been studied. Magnetite, Fe3O4, was initially formed after milling for short times. Nearly single-phase wustite, FeO, was found after milling for 30 h or longer. The kinetics of the phase transformations was studied by X-ray diffraction, Mossbauer spectroscopy and magnetic measurement. Nanocrystalline wustite formed during mechanical milling, decomposed into nanocrystalline Fe3O4 and Fe after annealing at 200-500 degrees C. Annealing at higher temperatures resulted in reformation of the wustite phase. (C) 1998 Elsevier Science B.V. All rights reserved.