Regensburg 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 32: Metal Substrates I

O 32.7: Vortrag

Dienstag, 12. März 2013, 12:00–12:15, H42

Interactions of oxidizing species with the Mg(0001) surface: the role of electrostatic contributions — •Su-Ting Cheng, Mira Todorova, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung GmbH

The adsorption of oxidizing species {N,O,F, Cl} on the Mg (0001) surface were studied using density functional theory. We observe a negative adsorbate-induced work function change and an increase in the binding energy with increasing adsorbate coverage, both of which fail to comply with common expectations regarding the adsorption of electronegative elements on a metal surface. Analysing the electronic structure we are able to explaine these changes in terms of a redistribution of electrons at the surface, which lowers the surface dipole. We find a correlation between the efficient embedding of the electronegative adsorbates into the electron spill-out from the Mg surface and the size of the adsorbate atoms. The special reduction of the electron spill-out furthermore causes a decrease in the electrostatic energy which dominates the binding energy within the studied adsorption system. The impact of these unusual trends on metal corrosion will be discussed.