Stability of helium-vacancy clusters in edge dislocations in bcc Fe

The a/2〈111〉{110} edge dislocation in bcc Fe was created using periodic array of dislocations methods. Molecular dynamic calculations were performed to study the stability of He-vacancy clusters in the dislocation core in bcc Fe, and the results were compared with simulations performed in perfect bcc Fe. The comparison show that the He-vacancy clusters are unstable for the effects of the dislocation field. The binding energies of an interstitial He atom, a vacancy and a self-interstitial Fe atom to the He-vacancy clusters depend mainly on the He-to-vacancy ratios of the clusters. In the dislocation core, for the ratio larger than 3 and less than 6, the binding energies are almost unchanging.