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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P12
Resonant Inelastic X-ray Scattering of Transition Metals and Transition
Metal Compounds
Wolfgang Caliebe 1 , Edmund Welter 1 , Pavel Machek 2
1 Hasylab am Desy, Notkestraße 85, 22607 Hamburg – 2 Institute of Organic and Ana-
lytical Chemistry, Justus Liebig Universität
We used a Johann spectrometer [1] to measure emission spectra of different transition
metals (TM) and transition metal compounds (TMC) while tuning the excitation
energy through the K-absorption edge. The energy resolution of the spectrometer is
better than 1 eV, while the energy resolution of the exciting x-ray beam is about 2 eV.
The emission lines excited above threshold show significant differences for different
compounds in case of Kβ1,3 and Kβ2,5 fluorescence lines, while there are just minor
differences for Kα1,2 fluorescence lines. The spectra excited close to threshold show
significant differences, and allow to separate transitions, which cannot be separated
with conventional x-ray absorption spectroscopy. We observe significant resonant enhancement
at the Cr K-edge, which allows to observe charge-transfer excitations in
K2CrO4 with an excitation energy of ≈3.3 eV, which is not observed off-resonance.
Additional observations are better separations of (weak) quadrupolar transitions in
the near-edge region from the dominating dipolar transition.
[1] E. Welter et al., J. Synchrotron Rad. 12 (2005) 448