Magnetic Investigation of the Annealing Behaviour of Some Dilute Iron–Nickel Alloys after Low-Temperature Electron Irradiation

Magnetic after-effect measurements are performed in the temperature range 4 to 350 H on a series of FeM alloys following irradiation at 44 K with 3 MeV electrons. Complicated relaxation processes are observed in which individual processes display a dependence on Ni content which is indicative of strong impurity trapping. These relaxation processes are interpreted in terms of intrinsic and mixed FeNi interstitial configurations. From an analysis of the concentration dependence of the Stage III (205 K) relaxation as well as from the formation of a low-temperature relaxation process at 11 K during anneal, new evidence in favour of a two-interstitial model is obtained.