Multilayered phase formation after high-fluence implantation of nickel into aluminium

The formation of crystalline and amorphous layers has been observed in Al crystals after 5MeV Ni implantation up to a fluence of 7.6 10 17 Ni atomscm -2 . The layers are structured into sublayers perpendicular to the implantation direction with sharp interfaces between the phases and almost symmetrically arranged to both sides of the maximum of the implantation profile. The sublayers of thickness of the order of 100nm were analysed by transmission electron microscopy. They consist of polycrystalline Al 3 Ni, crystalline Al 3 Ni precipitates and small amorphous zones, depending on the local Ni implantation concentration.