Determination of low-temperature interfacial energies from a pair interaction model

The chemical contribution to the energy of coherent interfaces is calculated from a pair interaction model, which represents an extension of the model presented by Becker in 1938. Nearest neighbour interaction is assumed, and entropy contributions are not considered. Concentration dependence of the pair interaction energies, as well as a change of crystal structure and/or a breakdown of long-range order at the interface are taken into account in the presented model. As examples, the interfacial energy is evaluated for coherent Cu–Co, Fe–Ag, and Cu–Cu4Ti interfaces. The necessary interaction parameters can be derived from the thermodynamic functions of the system determined experimentally or by thermodynamic calculations, e.g., by using the CALPHAD method.