Density functional theory calculations of He defect properties in Fe have shown an unexpected influence of magnetism arising from the defect's electronic structure. In contrast with previous work that neglected such effects, the results indicate that the tetrahedral position was energetically more favorable for the He interstitial than the octahedral site. This may have significant implications for He clustering and bubble nucleation, which will impact material performance in future fusion reactors. These results provide the basis for development of improved atomistic models.

Magnetic Interactions Influence the Properties of Helium Defects in Iron. T.Seletskaia, Y.Osetsky, R.E.Stoller, G.M.Stocks: Physical Review Letters, 2005, 94[4], 046403 (3pp)