Oxygen 2s spectroscopy of tin oxides with synchrotron radiation-induced photoemission
Autor: | J.-M. Gilles, Robert L. Johnson, J.-M. Themlin |
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Rok vydání: | 1994 |
Předmět: |
010304 chemical physics
Chemistry Binding energy Analytical chemistry General Physics and Astronomy chemistry.chemical_element Synchrotron radiation 02 engineering and technology Photoionization 021001 nanoscience & nanotechnology 01 natural sciences Oxygen X-ray photoelectron spectroscopy [PHYS.HIST]Physics [physics]/Physics archives Excited state 0103 physical sciences 0210 nano-technology Tin Spectroscopy |
Zdroj: | Journal de Physique IV Proceedings Journal de Physique IV Proceedings, EDP Sciences, 1994, 04 (C9), pp.C9-183-C9-186. ⟨10.1051/jp4:1994931⟩ |
ISSN: | 1155-4339 1764-7177 |
DOI: | 10.1051/jp4:1994931 |
Popis: | Oxygen 2s spectroscopy can be especially useful in studies using synchrotron radiation (SR) where the deeper O 1s level frequently can not be excited. For tin oxides (SnO and SnO2), the weak emission from the O 2s levels has been previously found degenerate with the intense photoemission peak from Sn 4d levels around a binding energy (BE) of 26 eV. By working at the Cooper minimum of the interfering tin signal, a distinct peak near BE ≈22.5 eV could be unambiguously attributed to emission from O 2s levels in tin oxides considering photoionization cross-section arguments. The O 2s intensity could now be used for the quantitative evaluation of the near-surface oxygen-species concentration. We have used the O 2s in combination with the Sn 4d areas to study the variations of the [Sn]/[O] ratio as a function of the preparation of a SnO2 single crystal. Although the dominant formal valence state for tin determined from a Sn 4d lineshape analysis remains essentially Sn4+, we show that this [Sn]/[O] ratio can vary from simple to double. This can be explained by oxygen interstitials buried in a sub-surface region during ion bombardment, which segregate at the surface upon annealing. |
Databáze: | OpenAIRE |
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