Temperature Mossbauer effect study of nanocrystalline FeMCuB alloys

Nanocrystalline Fe80M7B12Cu2 (M = Mo, Nb, Ti) alloys prepared from amorphou s precursors are investigated. Controlled annealing treatment in a protecti ve atmosphere favours the emergence of a bcc-Fe nanocrystalline phase, whic h was identified by X-ray diffraction, transmission electron microscopy and Fe-57 Mossbauer spectrometry. Magnetic behaviour of the nanocrystalline, a morphous as well as inter-facial phases is studied by Mossbauer effect meas urements performed in a wide temperature range (77-675 K) temperature depen dence of bcc-Fe hyperfine fields corresponding to nanosized grains deviate from those of a bulk alpha -Fe. The results are presented for different vol umetric fractions of crystallites and they are demonstrated on samples with different composition. In addition, magnetic structures of the disordered components are also discussed. (C) 2001 Elsevier Science B.V. All rights re served.