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 te mperature by X-ray absorption spectroscopy (XAS) and the long range order h as been studied by X-ray diffraction (XRD) in Fe-Co-Cu nanocrystalline allo ys prepared by mechanical alloying. In order to determine the time evolutio n of the alloying process, samples have been studied after several processi ng times. The joint analysis of XAS and XRD data shows a picture for the al loy formation in which, Co alloys with Cu in the first stages of the proces s but the iron enters the alloy phase much later than the cobalt does. On t he other hand, a refinement of the XRD data permits the identification of a residual iron phase previously detected by Mossbauer spectroscopy. (C) 199 9 Elsevier Science B.V. All rights reserved.