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MM: Fachverband Metall- und Materialphysik
MM 31: Postersitzung II
MM 31.21: Poster
Wednesday, March 16, 2011, 17:15–18:45, P5
X-ray Raman Scattering Studies of Si-based Compounds Under Extreme Conditions — •Christoph Sahle1, Christian Sternemann1, John Tse2, Max Wilke3, Christian Schmidt3, Alexander Nyrow1, Julien Dubrail3, Valentina Giordano4, Laura Simonelli4, Serge Desgreniers5, and Metin Tolan1 — 1Fakultät Physik/DELTA Technische Universität Dortmund, Otto-Hahn-Str. 4, 44227 Dortmund, Germany. — 2Department of Physics, University of Saskatchewan, Saskatoon S7N0W0, Canada. — 3Geoforschungszentrum Potsdam, Telegraphenberg, 14773 Potsdam, Germany. — 4ESRF, Rue Jules Horowitz, 38043 Grenoble Cedex, France. — 5Laboratoire de physique des solides denses, University of Ottawa, Ottawa K1N6N5, Canada.
The in situ study of low Z elements’ absorption edges under extreme conditions is only feasible using hard x-rays. Here, non-resonant x-ray Raman scattering as an energy loss technique enables one to choose the energy of the primary x-ray beam freely and thus gives access to shallow absorption edges of samples in highly absorbing sample environments, e.g. diamond anvil cells, which do not permit electrons and soft x-rays as probe. Here, we present two studies of Si-based compounds under extreme conditions: a high pressure study of the peculiar phase transitions in silicon clathrate Ba8Si46 via measurements of the Ba N45 and Si L23 edges. In addition, we present the first in situ high pressure – high temperature study at the Si L23 and Na L23 edge on hydrous Na2Si3O7 melt, which may serve as a model for geologically relevant hydrous silicate melts in the deep earth.