Modification and characterization of Al surfaces implanted with Cr ions

High fluence Cr+ implantations into polycrystalline aluminium samples were performed under different conditions of fluence and temperature. Rutherford backscattering spectrometry (RBS) was used to determine Cr distribution profiles, while the formation of Al–Cr intermetallic compounds was investigated by grazing incidence X-ray diffraction (GIXRD). Clear evidence for the direct formation of the intermetallic compounds Al86Cr14 and Al13Cr2 during ion implantation is presented. The influence of implantation temperature and fluence on the formation of these Al–Cr intermetallic compounds was also investigated. The stability of such intermetallic compounds was studied by means of annealing treatments, and it was found that the Al86Cr14 phase forms first and is then transformed into Al13Cr2 by a proper thermal annealing.