Binding enthalpies of carbon-vacancy complexes in α-Fe and their compatibility with different annealing models

The formation and dissociation of small carbon-vacancy (CV) complexes during the anneal of low-temperature electron(e-)-irradiated dilute FeC alloys is investigated systematically by means of the magnetic after-effect (MAE) technique. The kinetics of these defect reactions are analyzed quantitatively in order to investigate their compatibility with the predictions of either the one-interstitial (1 IM)- or the two-interstitial (2 IM)-annealing model. From these analyses the binding enthalpies of the complexes are determined and found to increase in proportion to their complexity within the range 0.1 eV≤HCVB≤0.65 eV. These values, together with additional details of the reaction kinetics, enable us to differentiate between the two annealing models in favour of the two-interstitial model (2IM). (author)