Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 49: Oxide and Insulator Surfaces: Adsorption
O 49.5: Poster
Dienstag, 21. März 2017, 18:30–20:30, P1A
DFT study of charged O2− adsorbed on Ca3Ru2O7(001) — Wernfried Mayr-Schmölzer, Florian Mittendorfer, and •Josef Redinger — Institute of Applied Physics, TU Vienna, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria
An atomic scale knowledge of the surface chemistry of perovskite oxides is surprisingly poor, despite their use in a wide range of important applications, like in sensors, or fuel cells, or even in catalytic processes. Here we present a DFT study of O2 adsorption on the (001) surface of Ruddelsden-Popper type Ca3Ru2O7. Experimentally Ca3Ru2O7 cleaves nicely, yielding an almost ideally flat rocksalt-like CaO(001) surface. However, due to the tilting and rotation of the RuO6 octahedra in the bulk different Ca-O distances are present, creating preferred adsorption sites for an O2 molecule. Upon adsorption O2 does not dissociate, but rather gets negatively charged. This charging is predicted both for the metallic and the insulating anti-ferromagnetically ordered substrate state, which exists below TN < 50K. We investigate the origin of the charge transfer using standard PBE, PBE+U and hybrid-functionals and find distinct differences concerning the local magnetic configuration for metallic and insulating states.