Ultrathin nickel oxide films grown on Ag(001): a study by XPS, LEIS and LEED intensity analysis
| Autor: | A. di Bona, Brunetto Cortigiani, Gianfranco Rovida, M. Caffio, Andrea Atrei, C. Giovanardi, Sergio Valeri |
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| Rok vydání: | 2003 |
| Předmět: |
Superstructure
Nickel oxide Non-blocking I/O Oxide Analytical chemistry chemistry.chemical_element Surfaces and Interfaces Condensed Matter Physics Epitaxy Surfaces Coatings and Films chemistry.chemical_compound Crystallography Nickel X-ray photoelectron spectroscopy chemistry Monolayer Materials Chemistry |
| Zdroj: | Surface Science. 531:368-374 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/s0039-6028(03)00544-2 |
| Popis: | The structure of a nickel oxide film 2 ML thick has been investigated by LEED intensity analysis. The NiO film was prepared by evaporating Ni in presence of O2 at a pressure in the 10 � 6 mbar range. The growth of the oxide film was followed by XPS,LEIS and LEED. In the early stages of deposition,the film shows a (2 � 1) superstructure in LEED. After deposition of 2 ML of NiO,a sharp (1 � 1) LEED pattern is observed. The intensity versus electron energy curves of the LEED spots were measured for this NiO(1 � 1) film and analysed by means of the tensor LEED method. A good level of agreement of the experimental LEED intensities with those calculated for a pseudomorphic NiO(0 0 1) film was obtained. We found that oxygen atoms at the oxide–substrate interface are on-top silver atoms. The interlayer distance in the oxide does not differ significantly from that in bulk NiO(0 0 1),within the accuracy of the analysis. An outward displacement (0.05 � 0.05 � of oxygen atoms with respect to nickel atoms was found at the oxide film surface. The interlayer distance at the silver–nickel oxide interface is 2.43 � 0.05 � 2003 Elsevier Science B.V. All rights reserved. |
| Databáze: | OpenAIRE |
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