Аннотация:The formation of a nanocrystalline state (10 nm) in α-Fe powders prepared by mechanical milling is not accompanied by changes in the structure and magnetic parameters in the case where the carbon content in the particles is below 0.03 wt %. The only exclusion is coercive force, which increases. In carbon-containing particles, all changes observed in Mössbauer spectra and in magnetic properties of nanocrystalline α-Fe particles with increasing milling time may be explained by carbon segregation in grain-boundary regions with the formation of supersaturated solid solutions or Fe3C.