title: Defect annihilation at grain boundaries in alpha-Fe.
abstract: Understanding radiation responses of Fe-based metals is essential to develop radiation tolerant steels for longer and safer life cycles in harsh reactor environments. Nanograined metals have been explored as self-healing materials due to point-defect recombination at grain boundaries. The fundamental defect-boundary interactions, however, are not yet well understood. We discover that the interactions are always mediated by formation and annealing of chain-like defects, which consist of alternately positioned interstitials and vacancies. These chain-like defects are closely correlated to the patterns of defect formation energy minima on the grain boundary, which depend on specific boundary configurations. Through chain-like defects, a point defect effectively translates large distances, to annihilate with its opposite, thus grain boundaries act as highly efficient defect sinks that cannot saturate under extreme radiation conditions.
authors.affiliation: Department of Nuclear Engineering, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Di
authors.initials: D
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Tianyi
authors.initials: T
authors.lastname: Chen
authors.forename: Lin
authors.initials: L
authors.lastname: Shao
mesh_terms: D006801:Humans; D007501:Iron / Q000737:chemistry* / Q000528:radiation effects; D009688:Nuclear Reactors; D055585:Physical Phenomena; D011827:Radiation; D055618:Radiation Equipment and Supplies
chemical_list: D007501:Iron