ABSTRACT
Atoms in the boundary between crystals must in general be displaced from positions they would occupy in the undisturbed crystal, but it is now well established that many interfaces have a periodic structure. In such cases, the misfit between the crystals connected by the boundary is not distributed uniformly over every element of the interface; it is localized periodically into discontinuities that separate patches of the boundary where the fit between the two crystals is good or perfect. The structure of an interface can be understood by creating a boundary beginning with a single crystal that is sliced and the two halves then rotated relative to generate two crystals in different orientations. For high-misorientation boundaries, the predicted spacings of dislocations may turn out to be so small that the misfit is highly localized with respect to the boundary, and the dislocation model of the interface has only formal significance.
