Formation of Al–Fe surface alloys by ion implantation of Fe in Al

High fluence Fe+ implantations were performed in commercial aluminium samples using two different iron isotopes, 56Fe+ and 57Fe+. The implanted layers were studied by Rutherford backscattering spectrometry, conversion electron Mِssbauer spectroscopy, grazing incidence X-ray diffraction, and scanning electron microscopy with energy dispersion spectroscopy. There is clear evidence for the direct formation of the Al5Fe2 intermetallic compound during ion implantation. The thermal stability of such an intermetallic phase was studied by means of annealing treatments, and it was found that it disappears after 1 h annealing at 630 °C and a new intermetallic compound, Al13Fe4, is formed.