6533b7d9fe1ef96bd126c0e1

RESEARCH PRODUCT

Adhesion trends and growth mode of ultra-thin copper films on MgO

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Ab initio simulations are performed for Cu atoms adsorbed on the perfect MgO(001) substrate, with an ordered metal coverage varied from 1 monolayer (ML), i.e. almost single atoms, up t o1M L. As trong dependence of the adhesion energy and the sub-monolayer film distance from the substrate on the surface coverage and adsorbate positions (Mg 2+ or O 2− )i s discussed. The nature of interfacial bonding at all coverages is physisorption .W hen increasing Cu atomic fraction, a decrease of the substrate-induced polarization of adatoms accompanied by an increase of both in-plane metallic bonding and the interfacial distance has been found. Combining results of ab initio calculations with thermodynamic theory (taking into account the lattice mismatch), we show that the metal cluster formation becomes the predominant growth mode even at low Cu coverages, in agreement with experiment. (Some figures in this article are in colour only in the electronic version)