Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 46: Nanostructures and Clusters
O 46.8: Vortrag
Mittwoch, 13. März 2013, 12:15–12:30, H45
XANES measurements on Ag clusters deposited in silica aerogel and ionic liquid — •David Engemann1, Sabrina Hoffmann1, Stefanie Duffe1, Christian Sternemann1, Kristina Kvashnina2, Pieter Glatzel2, Ralph Wagner3, and Heinz Hövel1 — 1Fakultät Physik / DELTA, Technische Universität Dortmund, 44221 Dortmund — 2ESRF, Grenoble, France — 3BU Wuppertal, Fachgruppe Physik-Materialwissenschaften, Wuppertal
Properties of clusters, in this case silver clusters, can differ widely from that of the corresponding bulk material. These differences correspond to the size of the clusters, their chemical environment and, in the case of deposited clusters, the supporting material. For most applications and measurements on deposited clusters it is necessary to deposit high amounts of clusters while protecting them from coalescence.
Silica aerogel is a very porous network (up to 99% empty space) of SiO2 nanoparticles with interparticle distances of about 50 nm. Depositing clusters (high amounts up to several cluster monolayers) in the nano-porous surface can prevent them from coalescence.
Clusters deposited in these matrices are still in contact to the gases in their surroundings. Chemical reactions like sulfidizing were investigated with plasmon resonance measurements and X-ray Absorption Near Edge Structure spectroscopy (XANES).
Further experiments with Ag clusters deposited in Room Temperature Ionic Liquids (RTIL) are in progress.