Ab initio modeling of copper adhesion on regular BaTiO₃(0 0 1) surfaces

Ab initio calculations have been performed for copper adsorption on a regular, defect-free TiO₂- and BaO-terminated (0 0 1) surfaces of a cubic BaTiO₃, using a posteriori HF-CC method as implemented into the CRYSTAL-03 computer code. To clarify the nature of the interfacial bonding, we use slab models of the Cu/BaTiO₃(0 0 1) interfaces with different one-side substrate coverages, varied from 1/8 monolayer (ML) up to 1/2 ML, over both TiO₂- and BaO-terminated surfaces. TiO₂ termination has been found to be energetically more favorable for the adsorption of copper atoms. In agreement with previous experimental and theoretical data, our calculations indicate essential contribution of atomic polarization into the interaction between Cu atoms and surface O^2- ions. An increase of substrate coverage by copper simultaneously reduces the binding energy (per adatom) and enhances the interatomic interactions inside growing metallic film.