Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 24: Postersitzung (Epitaxie und Wachstum, Oxide und Isolatoren, Elektronische Struktur, Oberfl
ächenreaktionen, Adsorption an Oberfl
ächen, Organische Dünnschichten)
O 24.15: Poster
Mittwoch, 26. März 2003, 14:30–17:30, P1
Structural and chemical properties of epitaxial aluminium oxide thin films grown on 1ML Fe/W(110) and W(110) measured by LEED and XPS — •Jacek Prokop, Andrei Kukunin, Marco Pratzer, and Hans-Joachim Elmers — Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, D-55099 Mainz
Epitaxial thin aluminium oxide layers were prepared by thermal oxidation (∼ 900 K, 1800 L) of 1nm thick Al layers deposited by MBE in UHV, on clean W(110) and on W(110) covered with a 1 monolayer (ML) thick Fe seed layer. The LEED pattern of the aluminium oxide films on clean W(110) reveals the existence of twin domains with a (
| 6 | 2 |
| −3 | 2 |
) superstructure, while aluminium oxide films on 1ML Fe(110)/W(110) show twin domain structures with an (
| 5 | −0.16 |
| 0 | 1.04 |
) incommensurate superstructure. The Al2O3/1ML Fe/W(110) layers were also prepared in a different way by Al evaporation in an oxygen atmosphere (p = 1.7×10−7 mbar) at room temperature and subsequent annealing. Before annealing, the aluminium oxide layers show no structural long range order and the iron layer becomes oxidized as was concluded from Fe 2p and O 1s XPS spectra. Annealing leads to a complete chemical reduction of the Fe monolayer and a formation of an ordered aluminium oxide layer with a similar structure as obtained by thermal oxidation. The mutual relation between characteristic shifts of the XPS Al lines and the structures of the aluminium oxide layers are compared to aluminium oxide bulk phases.