STUDY OF THE CARBON CONCENTRATION DISTRIBUTION IN IRON AND TITANIUM AFTER LOW-TEMPERATURE CARBON ION-IMPLANTATION

Carbon ion distribution profiles after implantation in iron and titani um were extensively investigated using Rutherford Backscattering Spect rometry (RBS) and Elastic Recoil Detection Analysis (ERDA). Ion energy and fluence were varied over large ranges using target temperatures o f less than -70 degrees C. In both systems a retention of a gaussian-l ike implantation profile was found up to very high fluences. Unexpecte d high values of local carbon concentration were obtained for high flu ences. Results were compared to Monte Carlo simulations using the dyna mical code TRIDYN. Additionally the influence of subsequent annealing on the carbon distribution was studied. The diffusive behaviour was fo und to be very different in both systems. The iron-carbon system shows strong rearrangement of carbon atoms and tries to achieve local conce ntrations of 25 at.% upon thermal treatment. In the corresponding temp erature regime no significant carbon diffusion in titanium takes place . (C) 1998 Elsevier Science B.V.