EN
Nanocrystalline (Fe₃Ni₁)₈₁Nb₇B₁₂ alloy was irradiated by electron beams of doses up to 4 MGy. Irradiation had an influence on the magnetic microstructure of the studied alloys. It has manifested as a change in the mean orientation of local magnetization, intensity of the internal magnetic field, and distribution function of induction of internal magnetic field. All these parameters were determined from the measured Mössbauer spectra. The mean orientation of local magnetization was the most sensitive parameter. Structural changes were not identified by the Mössbauer spectroscopy and by X-ray diffraction. The results indicated that the changes of the microscopic magnetic parameters induced by irradiation depend on the phase composition. Intensity of internal magnetic field also contributes to resistivity of alloy against radiation.