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 titanium were extensively investigated using Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA). Ion energy and fluence were varied over large ranges using target temperatures of less than -70 C. In both systems a retention of a gaussian-like implantation profile was found up to very high fluences. Unexpected high values of local carbon concentration were obtained for high fluences. Results were compared to Monte Carlo simulations using the dynamical code TRIDYN. Additionally the influence of subsequent annealing on the carbon distribution was studied. The diffusive behaviour was found to be very different in both systems. The iron-carbon system shows strong rearrangement of carbon atoms and tries to achieve local concentrations of 25 at.% upon thermal treatment. In the corresponding temperature regime no significant carbon diffusion in titanium takes place. (orig.)