Even the scattered photon does not forget – Electronic structure information in hard X-ray emission spectroscopy

by Pieter Glatzel (ESRF, Grenoble, France)

Friday 9 Jan 2015, 14:00 → 15:00 Europe/Berlin

CFEL Lecture Hall, Bldg. 99 (DESY Hamburg)

Electronic structure studies are generally the domain of soft X-ray spectroscopy because of smaller lifetime broadenings and favorable transition selection rules, e.g. at the L-edges of 3d transition metals. Many experiments are however incompatible with vacuum conditions and considerable effort is being made in adapting soft X-ray experimental stations for in situ experiments. Hard X-ray spectroscopy can readily be performed under in situ and extreme conditions but information on the electronic structure is not easily accessed. Photon-in/photon-out spectroscopy (XES, RIXS, X-ray Raman) provides considerably more possibilities for electronic structure studies than standard X-ray absorption spectroscopy. Therefore, "advanced" spectroscopies are being more and more considered by scientists who are interested in studying the chemical state under in situ or extreme conditions. Detailed electronic structure information can, however, only be derived from a spectrum when supported by theoretical modeling of the electron transitions and the photon scattering process. The presentation will show examples for the application of photon-in/photon-out spectroscopy in materials science and (bio)catalysis and how the properties retained by the scattered photon may point to the correct theoretical description of the electron transitions.