THERMAL AND AR ION-BEAM ANNEALING OF SURFACE AMORPHOUS LAYERS PRODUCED BY SB IMPLANTED INTO (100) NI SINGLE-CRYSTAL

The thermal and ion beam annealing of amorphous layers produced by the implantation of 10(17) ions cm-2 of Sb at 80 keV into (100) Ni was in vestigated using RBS/channelling techniques. The isochronal annealing process was carried out in the temperature range from 250 to 1100-degr ees-C, whereas the ion beam process involved the use of 1.5 MeV Ar+ io ns up to a fluence of 2.4 X 10(17) ions cm-2 at a constant temperature of 350-degrees-C. The results indicated that irrespective of the anne al process involved, the initial surface amorphous disorder caused by the implantation annealed out in two distinct stages. For Sb peak conc entrations above a critical value of 8-9 at.%, there was evidence of s ome possible form of segregation process occurring particularly during the isothermal annealing at 350-degrees-C. During this process, a par tial recovery of the crystalline lattice was observed together with on ly very slight diffusion of Sb atoms. When the Sb peak concentration f ell below this critical value, there was a second rapid anneal process which was accompanied with a long range diffusion of the Sb impuritie s in the Ni lattice. This further restoration of the crystalline latti ce was by no means perfect as the high dechannelling level of the obse rved RBS spectra indicated that an extensive number of dislocation net works still persisted in the surface layer even after prolonged anneal ing. Following the long range diffusion, the Sb atoms were observed to occupy substitutional sites in the good crystalline region of the Ni lattice.