Molecular dynamics simulations of screw dislocations, interacting with interstitial Frank loops, were performed by using specific boundary conditions in a model face-centered cubic crystal; in a configuration which was favorable to the formation of a helical turn on the dislocation. The interaction mechanism, and the pinning stress caused by the defects, were studied. It was shown that the interactions involved athermal cross-slip events, and that the shape of the loop had a strong influence. That is, loops with edges along <110> directions were unfaulted while loops with <121> edges were just sheared. The Frank loops were strong obstacles, with unpinning reactions that involved Orowan processes.

Molecular Dynamics Simulation of Screw Dislocations Interacting with Interstitial Frank Loops in a Model FCC Crystal. D.Rodney: Acta Materialia, 2004, 52[3], 607-14