Atomic structure characterization of an incommensurate grain boundary

The structure of an incommensurate 90°〈1 1 0〉 tilt grain boundary in gold was characterized by atomic resolution aberration-corrected electron microscopy and compared with atomistic simulations. Based on a periodic hyperspace description, the non-periodic structure can be described by the Aubry hull function, which plots atomic relaxations at the core of the boundary relative to an unrelaxed structure, folded into a single repeat unit of the neighboring grain. By measuring the hull functions from atomic resolution images, we were able to make quantitative comparisons of experimental observations with molecular statics simulations of this boundary. The results show good agreement in the pattern of atomic relaxations, replicate features of the hull functions that are characteristic of a boundary with superglide behavior and demonstrate the experimental feasibility of this approach for analysis of interfaces.