Dissociative adsorption of O2 molecules on O-precovered Fe(110) and Fe(100): Density-functional calculations

Autor(en)

Piotr Blonski, Adam Kiejna, Juergen Hafner

Abstrakt

The dissociative adsorption of O₂ molecules on clean and oxygen-precovered Fe(110) and Fe(100) surfaces has been studied from first principles. For the relatively open Fe(100) surface, we find that along the most favorable reaction channel, O₂ dissociation remains a nonactivated process up to almost full monolayer coverage. The differential heat of adsorption decreases only slowly with increasing oxygen precoverage. The potential energy profile for dissociation shows a dip, which is indicative of the formation of a very short-lived nonmagnetic peroxo precursor. On the close packed Fe(110) surface, the differential heat of adsorption begins to decrease already at a modest precoverage. For dissociation on a surface precovered with about 0.44 monolayer of oxygen, a low barrier begins to appear in the entrance channel. In the transition state, the incoming molecule is in a superoxo state with a magnetic moment of 1μB. Our results are discussed in relation to the electronic and magnetic properties of the partially precovered surfaces and to the available experimental results.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Uniwersytet Wrocławski

Journal

Physical Review B

Band

77

Anzahl der Seiten

8

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.77.155424

Publikationsdatum

2008

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/085561a8-598a-493a-ba56-007ddf5ce2b5