Characterization of tin oxides by x-ray-photoemission spectroscopy
| Autor: | J. Darville, Jean-Marc Themlin, J.-M. Gilles, Philippe Lambin, M. Chtaïb, Luc Henrard |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Physical Review B. 46:2460-2466 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.46.2460 |
| Popis: | Using well-defined samples of SnO and ${\mathrm{SnO}}_{2}$, we have focused our attention on the way the two tin oxides could be distinguished using x-ray-photoemission spectroscopy (XPS). Polycrystalline SnO, oxidized in air to give ${\mathrm{SnO}}_{2}$, sputtered by argon-ion bombardment to give SnO and single-crystalline ${\mathrm{SnO}}_{2}$ have been examined using XPS in order to study the formal valencies of tin in these partly ionic compounds. On the basis of a tin 3d-level line-shape analysis, we show that a sizable chemical shift of 0.7\ifmmode\pm\else\textpm\fi{}0.05 eV exists between (formal) ${\mathrm{Sn}}^{4+}$ and ${\mathrm{Sn}}^{2+}$. Using a least-squares fitting routine, we are able to follow the evolution of both ionic species upon argon-ion bombardment. This evolution shows up more strongly in the valence-band region, where SnO is characterized by an additional structure attributed to Sn 5s--derived levels. Our experimental results are interpreted using calculated tight-binding bulk densities of states. Finally, we propose a procedure for the quantitative evaluation, by XPS, of the relative concentration of the two oxides. |
| Databáze: | OpenAIRE |
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