Structure of Kurdjumov–Sachs interfaces in simulations of a copper–niobium bilayer

An interfacial atomic structure that contains a strained monolayer of copper is described for copper and niobium in the Kurdjumov–Sachs orientation relation. The interfacial monolayer accommodates the inherent misfit between the adjoining crystals. Computer simulations using embedded-atom potentials demonstrate that the improved coordination of interface atoms in this structure can offset the energy penalty associated with creating the strained Cu monolayer sufficiently to make this interface structure energetically favorable with respect to one created by simply joining two perfect Cu and Nb crystals. Insight gained from the analysis of this novel interface structure is applied to predicting what other pairs of materials may form interfaces that lead to improved radiation damage resistance, such as that observed in CuNb multilayer thin-film composites.