A Moessbauer study on the point defects induced by the radiation damage of metals

Aluminium containing 57Fe impurities has been irradiated at 77 K by 28 MeV electrons using KUR-LINAC in order to investigate the interactions between point defects and Fe solute atoms. 57Fe Moessbauer spectrum at 4.2 K obtained just after the irradiation consists of two components which are a main and a satellite component. Satellite component is attributed to the 57Fe in mixed-dumbbell of interstitials. Satellite intensity decreases abruptly at 15 K and disappeared completely at 60 K. Abrupt decrease of the intensity is due to the local jump of Fe in restricted geometry which is known as a cage motion of the interstitial in fcc lattice. Complemental techniques like resistivity measurements and the computer simulations based on the reaction kinetics have been performed and the binding energy between Fe and interstitials has been determined to be larger than 0.2 eV. (author)