Structural study of the mechanically alloyed Fe-Co-Cu nanocrystalline system

The local order around Fe, Co and Cu atoms has been investigated at room temperature by X-ray absorption spectroscopy (XAS) and the long range order has been studied by X-ray diffraction (XRD) in Fe-Co-Cu nanocrystalline alloys prepared by mechanical alloying. In order to determine the time evolution of the alloying process, samples have been studied after several processing times. The joint analysis of XAS and XRD data shows a picture for the alloy formation in which, Co alloys with Cu in the first stages of the process but the iron enters the alloy phase much later than the cobalt does. On the other hand, a refinement of the XRD data permits the identification of a residual iron phase previously detected by Mossbauer spectroscopy. (C) 1999 Elsevier Science B.V. All rights reserved.