Rutherford Backscattering and Channeling Studies of Laser Annealed, Nitrogen Implanted and Non-Implanted Single Crystal Austenitic Stainless Steel.

Ion backscattering and channeling of 2.0 MeV He+ has been used to observe the effects of excimer laser annealing on unimplanted and nitrogen implanted single crystal austenitic stainless steel. The laser annealing was done either in air or in flowing helium. In general, laser annealing resulted in a significant increase in lattice disorder of both unimplanted and implanted specimens. Laser annealing in helium atmosphere caused a near-surface decrease of disorder in the implanted specimens with, however, a higher dechanneling rate at greater depths. Channeling with nuclear reaction analysis shows that the as - implanted nitrogen occupies octahedral interstitial sites as evidenced by flux peaking along the <110> axis and a decreased signal along the <100> axis. A similar effect is observed after laser annealing in a helium atmosphere.