Effect of hydrogen on the magnetic characteristics of nanocrystalline iron

This paper reports the results of a complex investigation into the properties of nanocrystalline iron prepared through mechanical dispersion in a hydrogen atmosphere. Magnetic measurements reveal changes in the magnetic characteristics of iron samples obtained for different times of milling (i.e., samples with different grain sizes). The structural transformations responsible for these changes are studied by x-ray diffraction, Mössbauer spectroscopy, and thermogravimetry. It is found that incorporation of hydrogen into the boundary region between single-domain particles of consolidated nanocrystalline iron leads to an increase in the coercive force. Magnetic anisotropy induced by strains is observed. It is established that the strain-induced magnetic anisotropy affects the field dependence of the saturation magnetization of nanocrystalline iron.