Infrared spectroscopic study of the CO-mediated decrease of the percolation threshold during the growth of ultrathin metal films on MgO(001)
| Autor: | Annemarie Pucci, A. Priebe, G. Fahsold, M. Lust |
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| Rok vydání: | 2002 |
| Předmět: |
Absorption spectroscopy
Infrared Analytical chemistry Infrared spectroscopy chemistry.chemical_element Percolation threshold Surfaces and Interfaces General Chemistry Condensed Matter Physics Copper Surfaces Coatings and Films Metal chemistry Transition metal Percolation visual_art Materials Chemistry visual_art.visual_art_medium |
| Zdroj: | Surface and Interface Analysis. 33:487-490 |
| ISSN: | 1096-9918 0142-2421 |
| DOI: | 10.1002/sia.1236 |
| Popis: | Metals are known to grow three-dimensionally on clean ionic crystal surfaces with low surface energies. As a consequence, the naturally grown films consist of islands and are non-conductive up to the percolation threshold, which is at 1 nm for iron films grown on MgO(001) at room temperature and is much larger for noble metals and higher temperatures, respectively. In this paper we show that CO exposure at 10 -8 mbar during deposition modifies the growth on MgO(001) for iron and copper. The development of infrared transmission spectra versus metal film thickness clearly is changed by CO exposure. The spectral differences correspond to a significant percolation threshold decrease induced by CO. Infrared conductivity parameters calculated from transmittance spectra indicate that the surface relaxation of the free charge carriers is decreased due to CO exposure during growth but the plasma frequency is unchanged. |
| Databáze: | OpenAIRE |
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