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

Author(s)
Piotr Blonski, Adam Kiejna, Juergen Hafner
Abstract

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(s)
Computational Materials Physics
External organisation(s)
University of Wrocław
Journal
Physical Review B
Volume
77
No. of pages
8
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.77.155424
Publication date
2008
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter
Portal url
https://ucrisportal.univie.ac.at/en/publications/dissociative-adsorption-of-o2-molecules-on-oprecovered-fe110-and-fe100-densityfunctional-calculations(085561a8-598a-493a-ba56-007ddf5ce2b5).html