The adsorption of oxygen on the Pt3Sns110d alloy surface was studied by means of scanning tunneling microscopy sSTMd and low-energy electron diffraction sLEEDd. After exposure to 2300 L O2 at 750 K LEED shows additional cs232d spots with regard to the substrate ps231d pattern. This agrees straightforward with STM topographies revealing a thin layer of large protrusions, arranged in a pseudohexagonal lattice. This layer is split into domains separated by distinctive zigzagging boundaries. Post-annealing allowed to partially uncover substrate regions. That way it could be shown that the protrusions are located above Sn locations. Further post-annealing restored the original substrate completely. A model of the adlayer structure consistent with all STM and LEED findings is given. These features observed after high temperature oxygen exposure of the Pt3Sns110d surface resemble to a large extent structures obtained on the Pt3Sns111d surface under similar conditions. The observed structures can be understood in terms of Sn-O entities interacting with each other. However, results from the oxidation of Pt3Sns111d indicate the formation of a Sn layer with chemisorbed oxygen on top, but not of separated SnOx entities. The protrusion patterns observed with STM on both surfaces are a topographic signature of such Sn-O layers on Pt3Sn.
|Titolo:||Adsorption of oxygen on Pt3Sn 110 studied by STM and LEED|
|Citazione:||M., H., S., S., Atrei, A.M., U., B., & G., R. (2005). Adsorption of oxygen on Pt3Sn 110 studied by STM and LEED. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 71(3), 035410-1-035410-7.|
|Appare nelle tipologie:||1.1 Articolo in rivista|