Effect of hydrogen on the magnetic characteristics of nanocrystalline iron

This paper reports the results of a complex investigation into the properti es of nanocrystalline iron prepared through mechanical dispersion in a hydr ogen atmosphere. Magnetic measurements reveal changes in the magnetic chara cteristics of iron samples obtained for different times of milling (i.e., s amples with different grain sizes). The structural transformations responsi ble for these changes are studied by x-ray diffraction, Mossbauer spectrosc opy, and thermogravimetry. It is found that incorporation of hydrogen into the boundary region between single-domain particles of consolidated nanocry stalline iron leads to an increase in the coercive force. Magnetic anisotro py induced by strains is observed. It is established that the strain-induce d magnetic anisotropy affects the field dependence of the saturation magnet ization of nanocrystalline iron. (C) 2001 MAIK "Nauka/Interperiodica".