A novel grain-boundary structural phase transition was found in both molecular-dynamics and phase-field-crystal simulations of classical models of body-centered cubic Fe. This transition was characterized by pairing of individual dislocations with mixed screw and edge components. It was demonstrated that this type of transition was driven by a combination of factors including elastic softening, core interaction, and core disordering. At high homologous temperatures the occurrence of this transition was shown to prevent pre-melting at misorientation angles where it would otherwise be expected.

Dislocation-Pairing Transitions in Hot Grain Boundaries. D.L.Olmsted, D.Buta, A.Adland, S.M.Foiles, M.Asta, A.Karma: Physical Review Letters, 2011, 106[4], 046101