Berlin 2015 – wissenschaftliches Programm
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KR: Fachgruppe Kristallographie
KR 2: Poster Crystallography
KR 2.4: Poster
Montag, 16. März 2015, 19:00–21:00, Poster C
Structural Information Beyond the Ensemble Average From Colloidal Crystals Using X-Ray Cross-Correlation Analysis — •Matthias Kampmann1,2, Michael Sprung1, Bill Pedrini3, Tushar Sant2, Falko Ziegert4, and Christian Gutt2 — 1DESY, Hamburg, Germany — 2Universität Siegen, Germany — 3Paul Scherrer Institut, Villigen, Switzerland — 4Universität Rostock, Germany
Fluctuations in X-ray scattering intensity from particle ensembles carry structural information beyond the pure ensemble average, which can be mined using X-ray cross correlation analysis (XCCA). Kam was the first to propose applying higher order intensity correlation functions to solution scattering data of macromolecules for obtaining structural information [Kam1]. His ideas were far beyond the power of X-ray sources and detectors in the 1970s. But they gained new interest with the ultrafast snapshot capabilities of X-ray free-electron laser sources, not only for solving particle structures but also in a more statistical context for densely packed systems [Wochner].
Here we present an XCCA analysis of diluted suspensions of small micrometer sized colloidal crystals. In a coherent X-ray scattering experiment we have measured several thousand diffraction patterns of colloidal sample systems and calculated the corresponding higher order correlation functions. The data reveal strong angular modulations of the XCCA signal, which are a fingerprint of the single particle diffraction properties.
Kam1: Z. Kam, Macromolecules 10, 927-934 (1977)
Wochner: P. Wochner et al., PNAS 106, 11511-11514 (2009)