Single SIA migration in concentrated FeCr alloys

The defect recovery stages in Fe-Cr alloys containing 5, 10 and 15%Cr have been modelled using rate equations, under three main assumptions: (i) traps for single SIA exist and their concentration depends on Cr content, (ii) the migration energy of the single SIA (when not trapped) depends on the Cr content as well and decreases compared to pure Fe; (iii) the vacancy migration energy is largely unaffected by the presence of Cr. The first assumption is suggested by both resistivity recovery experiments in concentrated alloys and ab initio calculations]; the second one is suggested by resistivity recovery experiments in diluted alloys and confirmed by (yet unpublished) MD simulations; the third one is suggested by a number of experiments (here uncited) and ab initio calculations. The model provides reasonable agreement with experimental data from. From the model it can be deduced that by increasing the Cr content in the limit of 5-15%Cr the concentration of traps for the SIA increases drastically (three order of magnitude); the trapping energy increases as well. Including a consistent treatment of migration properties for small interstitial clusters is the next step to be taken.