Abstract
We performed a DFT modelling of Al2O3(001)/Al(001) and Al2O3(001)/Al2Cu(001) surfaces and of Al(010)/Al2Cu(010) interfaces covered with Al2O3(001). We focus on the electronic properties (work function, valence band and electronic gap) computed for the different models. We show that both on Al and Al2Cu, the oxide layer induces a significant increase in work function. The effect of the composition of the first metallic layer underneath the oxide film is also investigated. Cu enrichment under the oxide film induces an increase in work function, however less marked than the one caused by the oxide layer. We show that the work function increase is due to a charge transfer from the interfacial metal layer to the oxide layer. The same result is found at the oxidized Al(010)//Al2Cu(010) interface. The work function of the oxidized Al2Cu zone is higher than the one of oxidized Al.
Highlights
We showed that Cu monolayer segregation underneath the oxide film at low concentration tends to increase the work function, whereas a decrease of the work function by 0.3 eV is calculated at high concentration.[3]
Valence and conduction bands of the Al2O3 ultrathin layers above Al(001) and Al2Cu(001) surfaces.—We study the Valence band (VB) and Conduction band (CB) positions of Al2O3 on Al and Al2Cu
Application to the systems of interest for corrosion.—In the preceding part, we have shown that the work function increases with the presence of the Al2O3 oxide layer and with the increasing nobility of the metal underneath the oxide film, and that the determining parameter for the Φ value change is the charge transferred to the oxide, the oxidation degree of the metallic plane underneath the oxide
Summary
Relation between Surface Composition and Electronic Properties of Native Oxide Films on an Aluminium-Copper Alloy Studied by DFT. HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Soc. 167 161501 View the article online for updates and enhancements.
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