title: Properties of Pt-supported iron oxide ultra-thin films: similarity of Hubbard-corrected and hybrid density functional theory description.
abstract: We report a first principles study on the properties of Pt(111)-supported FeO(111) monolayer. We confront results issued from PBE+U and HSE06 approximations, and analyze the impact of the more accurate hybrid description of the electronic structure of the metal/oxide interface on a large variety of calculated characteristics of this system. In particular, we analyze the behavior of its work function and its consequences on the spontaneous charging of adsorbed Au adatoms. We also consider the FeO2 nano-oxide phase and its peculiar oxygen storage characteristics, responsible for the unusual catalytic properties of FeO(x)/Pt system. We show that while the hybrid approximation does indeed substantially improve the electronic characteristics of iron oxide, of individual Au adatoms, or oxygen molecules, its overall impact on the calculated properties of the composed FeO/Pt system is very small. We assign this to the relatively small effect of the hybrid approximation on the band structure alignment. This shows that the less computationally demanding DFT+U approximation remains a fully adequate tool in theoretical studies on this kind of systems. This is particularly important for calculations on realistic systems, with large-size reconstructions induced by the lattice mismatch at the interface between the two materials.
authors.affiliation: Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, via Cozzi, 55 - 20125 Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Prada
authors.affiliation: Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, via Cozzi, 55 - 20125 Milano, Italy.
authors.forename: Livia
authors.initials: L
authors.lastname: Giordano
authors.affiliation: Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, via Cozzi, 55 - 20125 Milano, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pacchioni
authors.affiliation: CNRS, UMR 7588, Institut des Nanosciences de Paris, F-75005 Paris, France.
authors.forename: Claudine
authors.initials: C
authors.lastname: Noguera
authors.affiliation: CNRS, UMR 7588, Institut des Nanosciences de Paris, F-75005 Paris, France.
authors.forename: Jacek
authors.initials: J
authors.lastname: Goniakowski