Regensburg 2002 – wissenschaftliches Programm
O 39.1: Vortrag
Freitag, 15. März 2002, 11:15–11:30, H44
Surface oxidation of SnO2−x nanoparticles — •Ramasamy Ramamoorthy1,2, Marcus Kennedy1, Hermann Nienhaus2, Axel Lorke2, Einar Kruis1, and Heinz Fißan1 — 1Prozess-und Aerosolmesstechnik — 2Laboratorium für Festkörperphysik, Gerhard-Mercator Universität Duisburg
The high surface-to-volume ratio of the nanoparticles enables improving the sensitivity of the SnO2 gas sensors. As a little is known about the surface chemistry of tin oxide nanoparticles, the study of their surface stoichiometry has become an important aspect of understanding the sensing phenomena. We deposited mono-dispersed tin oxide nanoparticles with different stoichiometry and different size (10- 30 nm) on silicon substrates by an aerosol method. Auger electron and X-ray photoelectron spectroscopy were applied to the as-deposited and post heat-treated SnO2−x nanoparticles. The results show that the oxygen content at the particle surfaces varies drastically after different heat treatments and the variation is influenced by the initial oxygen content, the time-temperature history of the heat treatments and the particle size. For a given heat treatment in air, the SnO gets oxidized and the SnO2 looses oxygen in the nanocrystalline state.