High energy resolution off-resonant spectroscopy for x-ray absorption spectra free of self-absorption effects.
X-ray emission spectra recorded in the off-resonant regime carry information on the density of unoccupied states. It is known that by employing the Kramers-Heisenberg formalism, the high energy resolution off-resonant spectroscopy (HEROS) is equivalent to the x-ray absorption spectroscopy (XAS) technique and provides the same electronic state information. Moreover, in the present Letter we demonstrate that the shape of HEROS spectra is not modified by self-absorption effects. Therefore, in contrast to the fluorescence-based XAS techniques, the recorded shape of the spectra is independent of the sample concentration or thickness. The HEROS may thus be used as an experimental technique when precise information about specific absorption features and their strengths is crucial for chemical speciation or theoretical evaluation.
Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
W
W
Błachucki
Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland and Institute of Physics, Jan Kochanowski University, 25-406 Kielce, Poland.
J
J
Szlachetko
Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
J
J
Hoszowska
Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
J-Cl
JC
Dousse
Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
Y
Y
Kayser
Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland.
M
M
Nachtegaal
Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland.
J
J
Sá