Mössbauer and X-ray diffraction investigation of nanocrystalline Fe–O alloys

X-rayand M . ossbauer investigations were carried out on powders produced bymilling of Fe 2O3+a-Fe mixtures in a high-energy ball mill and subsequent low-temperature annealing. The nanocrystalline composite alloys obtained as a result of the milling, contained FeO and a-Fe with an average crystallite size of 15–20 nm as well as an amorphous phase. Alloys subjected to subsequent annealing contained, however, only a-Fe+Fe3O4 with an average crystallite size of about 20 nm. Unlike the starting materials the produced powders had properties, which are characteristic for hard magnetic materials. r 2002 Elsevier Science B.V. All rights reserved.