On the correlation between self-interstitial cluster diffusivity and irradiation-induced swelling in Fe-Cr alloys

It is shown that the dependence of self-interstitial cluster diffusivity in Fe–Cr alloys on Cr concentration correlates with that of swelling in these alloys under neutron irradiation; namely, with increasing chromium concentration the cluster diffusivity first decreases and then increases. The origin of such behaviour lies in a relatively long-ranged, 1 nm, attractive interaction between Cr atoms and crowdions. The minimum diffusivity is realized for 11 at.% Cr, where all crowdions constituting the cluster interact with Cr atoms, but the interaction fields of different Cr atoms do not overlap.