Transmission 57Fe Mössbauer spectroscopy, J-H quasistatic hysteresis loop and AC susceptibility measurements are used to study effects of neutron irradiation on magnetic properties of Fe-based ferromagnetic metallic glasses. Elastic stress centers are produced during the process of neutron irradiation as a result of atom mixing. Rearrangement of the atoms causes changes in the average value of the hyperfine field distribution and orientation of the net magnetic moment. They are shown to depend on the composition of the investigated samples. Cr-doped metallic glasses depict transition from the ferromagnetic to paramagnetic state at room temperature after neutron irradiation implying changes in the Curie temperature. The presence of Ni in the samples reduces the effects of radiation damage as revealed also from positron lifetime data. Possible sources of a radiation damage are discussed using the results of γ-ray spectroscopy.
(Received September 2, 1991)
Keywords: metallic glasses, neutron irradiation, hyperfine parameters, Mössbauer spectroscopy, magnetic measurements
† On leave from the Department of Nuclear Physics and Technology, Slovak Technical University, Mlynská dolina, CS-812 19 Bratislava, Czechoslovakia.
†† Present address: GKSS Forschungszentrum, Institute für Werkstofforschung, Max-Planck Strasse, D-2054 Geesthacht, Germany.