The large penetration depth of a hard X-ray probe is interesting in a broad range of applications in materials science research because of its bulk sensitivity and the compatibility with in-situ conditions. Most hard X-ray techniques, however, address the atomic structure while analysis of the electronic configuration is hampered by the large spectral broadening and only few tools for theoretical analysis are available. The presentation will discuss the information that can be obtained on the electronic structure using resonant hard X-ray emission spectroscopy. The various techniques including magnetic circular dichroism will be briefly introduced and recent results on Pt, CeO2 and Fe3O4 nanoparticles will be presented.
The full information content in inner-shell spectra can only be accessed by theoretical modeling of the data. We used density functional theory (FEFF, ORCA, Wien2k) codes and ligand field multiplet theory to simulate the experimental data. We find that many spectra can be modeled using a surprisingly simple approach. This allows for a detailed analysis of the electronic structure. The limitations of this approach are discussed.