Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 33: Molecular Structure
CPP 33.1: Vortrag
Donnerstag, 28. Februar 2008, 15:00–15:15, C 230
The structure of liquids studied by soft x-ray emission (XES) and absorption (XAS) spectroscopy — •M. Blum1, O. Fuchs1, M. Weigand1, F. Maier1, E. Umbach1,2, L. Weinhardt3, M. Bär3, C. Heske3, M. Zharnikov4, Y. Zubavichus4, M. Grunze4, and J.D. Denlinger5 — 1Universität Würzburg, Experimentelle Physik — 2Forschungszentrum Karlsruhe — 3University of Nevada, Las Vegas — 4Angew. Physikal. Chemie, Uni Heidelberg — 5ALS, Berkeley
Recently, soft x-ray XES and XAS techniques have been employed to probe the electronic structure of liquids. Such experiments represent a technically challenging task, since they require a third-generation synchrotron source and a liquid cell with a thin window separating the liquid from ultra-high vacuum. XES is particularly elaborate in this respect, since it requires a high-efficiency grating spectrometer. With our flow-through liquid cell and a novel high-transmission, high-resolution x-ray spectrometer we have investigated the electronic structure of various liquids including H2O, D2O, NaOH, NaOD, acetic acid, amino acids, and various other aqueous solutions under well-defined and reproducible conditions. We will present 2-dimensional resonant inelastic x-ray scattering (RIXS) maps of these liquids, which give unprecedentedly detailed information on the electronic structure. The XES spectra of water show effects that can be correlated with molecular dynamics on the time scale of the core hole lifetime. Moreover, the maps of the aqueous solutions reveal subtle changes in the electronic structure which can be attributed to the influence of the hydration shell and the pH-value.