Formation of epitaxial NiO by oxygen implantation in [100] Ni

18O has been implanted at room temperature up to doses of 4.4 x 1017/cm2 in a [100] Ni crystal. The implantation energy was 60 keV. Backscattering and channeling analyses at various implantation steps give evidence for oxygen migration towards the surface. After the overall implantation, X-ray analysis reveals the presence of NiO in epitaxy [100]parallel[100] with the substrate. Backscattering and channeling experiments tend to indicate that between the surface and Rsub(p) the sample is formed of NiO epitaxial crystallites and of pure nickel leading to a mean stoichiometry NiO0sub(.)75, constant in depth up to Rsub(p). The misfit between the Ni and NiO lattice parameters induces strains and extended defects formation. Between Rsub(p) and Rsub(p) + ΔRsub(p) the oxygen concentration decreases, and the channeling results show no preferential direction. This region corresponds probably to a highly disordered Ni-O alloy. This hypothesis is confirmed by annealing experiments: the oxygen present between Rsub(p) and Rsub(p) + ΔRsub(p) migrates towards the surface at 4000C and a reordering of this region is observed. There is also an improvement of the structural quality of the NiO crystallites. (orig.)