Modeling interatomic interactions across Cu/α–Al2O3 interface

With the use of the universal binding-energy relation we fit the pair interatomic potentials describing the interaction across Cu(1 1 1)/α–Al2O3(0 0 0 1) interface to the results of rigid tensile test obtained by ab initio calculations for oxygen rich and stoichiometric sapphire terminations. The corresponding two sets of Cu–O and Cu–Al potentials are quite different because of the different bonding nature at the oxygen-rich and stoichiometric interfaces. Assuming that, with certain care, these potentials can be used for other sapphire orientations and terminations having similar near-surface coordination of atoms, we carry out crystallographic analysis of various sapphire surfaces and find a number of such cases, thus extending the applicability of the fitted potentials.