The atomic structure of an asymmetrical near Σ = 27 {525} tilt grain boundary in copper was determined by coupling high-resolution transmission electron microscopy and molecular dynamics simulation. The average grain boundary plane was parallel to {414} in crystal (1) and {343} in crystal (2). The detailed grain boundary structure shows that it was composed of facets always parallel to {101} and {111} in crystals (1) and (2), respectively. The atomic structure of one facet was described using the structural units model. Each facet was displaced with respect to its neighbours by a pure step, giving rise to the asymmetry of the grain boundary plane orientation. The energy of this asymmetrical grain boundary was significantly lower than that of both the {525} symmetrical and the {11,1,11]/{111} asymmetrical Σ = 27 grain boundaries. One grain boundary region displays another atomic structure with a dislocation that accounts for the misfit between interatomic distances in the {414} and {343} grain boundary planes.

On the Atomic Structure of an Asymmetrical Near Σ = 27 Grain Boundary in Copper. J.P.Couzinié, O.H.Duparc, S.Lartigue-Korinek, J.Thibault-Pénisson, B.Décamps, L.Priester: Philosophical Magazine Letters, 2009, 89[12], 757-67