Preparation of Cu(110)-Fe alloys and their reactivity towards oxygen

doi:10.1016/0169-4332(87)90017-1

Applied Surface Science

Volume 29, Issue 1, August–September 1987, Pages 86-100

https://doi.org/10.1016/0169-4332(87)90017-1 Get rights and content

Abstract

Cu(110)-Fe alloys are prepared by thermal decomposition of Fe(CO)₅ at 600 K. Iron facets grow under an inclination angle of 35.2° with the surface exposing a (110) plane. The majority of iron is distributed below the surface layer and there is hardly any enrichment of copper at the surface layer. Oxygen adsorption is not noticably accelerated compared to that on Cu(110). At temperatures below 400 K even a decrease in sticking coefficient is noticed. The total oxygen uptake increases with temperature and iron content.

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Ultrathin films of iron have been prepared on Cu(110) and the interaction with oxygen studied with LEED and XPS. Chemical shifts of the $Fe2p_{32}$ XPS signal indicate that sub- to a few monolayer amounts of iron on Cu(110) can be oxidized to FeO, then Fe₃O₄ or possibly γ-Fe₂O₃. A mild annealing of a heavily oxidized iron overlayer leads to an appearance of a new LEED pattern with hexagonal symmetry that is assigned to Fe₃O₄, though the possibility of γ-Fe₂O₃ is not fully eliminated. Another LEED pattern is observed for surfaces giving an $Fe2p_{32}$ binding energy at 709.5 eV which is typical of an FeO overlayer. Annealing the Fe₃O₄ overlayer up to 930 K converts both XPS and LEED features back to those assigned to FeO.
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Preparation of Cu(110)-Fe alloys and their reactivity towards oxygen

Abstract

Surface Sci.

Appl. Surface Sci.

Surface Sci.

Surface Sci.

Surface Sci.

Appl. Surface Sci.

Surface Sci.

Surface Sci.

Surface Sci.