The interaction of P impurity atoms with primary radiation defects was investigated by using the molecular dynamics method and Morse-like potentials. It was concluded that the substitution of a P atom produced a considerable region in which a self-interstitial dumb-bell could be captured, and this event could result in a transition of P from the low-mobility substitutional state to give a mixed P-Fe dumb-bell. The latter could rearrange itself into an energetically more efficient tetrahedral interstitial. Such reactions produced an increase in P mobility under irradiation at low temperatures; where the vacancy mechanism for impurity migration was not operative.

A.A.Vasiliev, V.V.Rybin, A.A.Zisman: Journal of Nuclear Materials, 1996, 231[3], 249-53