Vacancy loop formation in hydrogen-ion-implanted alpha-iron

Abstract
To investigate the behaviour of hydrogen in irradiated iron at high temperature, electron-irradiation and defect analysis have been carried out in a high-voltage electron microscope after H+−ion implantation. After the implantation, visible interstitial-type loops were formed at room temperature. However, in iron implanted at low temperature, fine vacancy-type loops developed during annealing at above 720 K and these shrunk under further electron irradiation. These results indicate that injected hydrogen can interact with vacancies and cause the formation of vacancy-type loops.