The effect of a He atom upon the migration of self-interstitial dislocation loops with a Burgers vector ½<111> in body-centred cubic Fe was investigated by using molecular statics and molecular dynamics simulations. It was found that an interstitial He atom hindered the migration and coalescence behavior of dislocation loops by strongly binding to the loop on the edge sites. An unstable interstitial He atom on the loop plane easily moves to the stable edge sites by interstitial diffusion. A substitutional He atom did not significantly disturb the migration of dislocation loops, showing weak binding.

Atomistic Modeling of the Interaction between Self-Interstitial Dislocation Loops and Helium in BCC Fe. J.H.Shim, S.C.Kwon, W.W.Kim, B.D.Wirth: Journal of Nuclear Materials, 2007, 367-370[1], 292-7