Oxidation of Pd(553): From ultrahigh vacuum to atmospheric pressure

Autor(en)

Rasmus Westerström, Johan Gustafson, Andrea Resta, Anders Mikkelsen, Jesper N. Andersen, Edvin Lundgren, Nicola Seriani, Florian Mittendorfer, Michael A. Schmid, J Klikovits, Peter Varga, M. D. Ackermann, Joost W M Frenken, N Kasper, Andreas Stierle

Abstrakt

The oxidation of a vicinal Pd(553) surface has been studied from ultrahigh vacuum (UHV) to atmospheric oxygen pressures at elevated sample temperatures. The investigation combines traditional electron based UHV techniques such as high resolution core level spectroscopy, low-energy electron diffraction, scanning tunneling microscopy with in situ surface x-ray diffraction, and ab initio simulations. In this way, we show that the O atoms preferentially adsorb at the step edges at oxygen pressures below 10-6 mbar and that the (553) surface is preserved. In the pressure range between 10-6 and 1 mbar and at a sample temperature of 300-400°C, a surface oxide forms and rearranges the (553) surface facets and forming (332) facets. Most of the surface oxide can be described as a PdO(101) plane, similar to what has been found previously on other Pd surfaces. However, in the present case, the surface oxide is reconstructed along the step edges, and the stability of this structure is discussed. In addition, the (6×6) Pd5 O4 surface oxide can be observed on (111) terraces larger than those of the (332) terraces. Increasing the O pressure above 1 mbar results in the disappearance of the (332) facets and the formation of PdO bulk oxide.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Lund University, Technische Universität Wien, Leiden University, Max-Planck-Institut für Metallforschung

Journal

Physical Review B

Band

76

Anzahl der Seiten

9

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.76.155410

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/db9bd8af-2f68-4e1e-9e67-a4b2e5828317