Moessbauer and X-ray diffraction investigation of nanocrystalline Fe-O alloys

X-ray and Moessbauer investigations were carried out on powders produced by milling of Fe2O3+α-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 α-Fe with an average crystallite size of 15-20 nm as well as an amorphous phase. Alloys subjected to subsequent annealing contained, however, only α-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