title: Dislocation-pairing transitions in hot grain boundaries.
abstract: We report the finding of a novel grain-boundary structural phase transition in both molecular-dynamics and phase-field-crystal simulations of classical models of bcc Fe. This transition is characterized by pairing of individual dislocations with mixed screw and edge components. We demonstrate that this type of transition is driven by a combination of factors including elastic softening, core interaction, and core disordering. At high homologous temperatures the occurrence of this transition is shown to prevent premelting at misorientation angles where it would otherwise be expected.
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Olmsted
authors.forename: Dorel
authors.initials: D
authors.lastname: Buta
authors.forename: Ari
authors.initials: A
authors.lastname: Adland
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Foiles
authors.forename: Mark
authors.initials: M
authors.lastname: Asta
authors.forename: Alain
authors.initials: A
authors.lastname: Karma