Mechanically alloyed Cu-Fe studied by Mossbauer spectroscopy

Recent studies of mechanically alloyed Fe-Cu powder mixtures have suggested differences in the local magnetic environment of iron atoms. For a more ac curate definition of this point, ball-milled Cu70Fe30 and Cu50Fe50 alloys w ere investigated by Mossbauer spectroscopy in the, temperature range 4.2-30 0 K. The low temperature Mossbauer spectra exhibit a broad magnetic pattern . typical of a defect structural configuration. The magnetic splitting stro ngly decreases with increasing temperature, especially in the case of Cu70F e30 alloy. But even for this composition there is, at room temperature, an unresolved magnetic pattern. Applying a magnetic field of 3 T, parallel to gamma rays, at 4.2 K a rotation of all magnetic moments along the external field is observed. The samples behave as an alloy with continuously distrib uted local fields. (C) 2001 Elsevier Science BY. All rights reserved.