Jindrich Kolorenc1

1, Czech Academy of Sciences, Prague, , Czechia

I discuss a theoretical description of the resonant x-ray emission spectroscopy (RXES) that is based on the Anderson impurity model. The parameters of the model are determined from material-specific LDA+DMFT calculations. Recently, this approach was shown [1] to accurately reproduce the L-edge RXES measured in lanthanides [2]. Here, the method is extended to the M-edge spectra in actinide compounds. The same theoretical approach applies also to the x-ray absorption spectra measured in the high-energy-resolution fluorescence-detection mode (HERFD-XAS) [3]. As an example, I investigate the origin of large variations observed among the M-edge HERFD-XAS spectra of uranium compounds where uranium atoms are in the same oxidation state. For instance, both UO3 and torbentite have U atoms in the U(VI) state, but the shape of their x-ray absorption spectra differs quite substantially [4,5].
[1] J. Kolorenč, Physica B (2017), DOI: 10.1016/j.physb.2017.08.069
[2] J. A. Bradley et al., Phys. Rev. B 85, 100102 (2012).
[3] K. Hämäläinen, D. P. Siddons, J. B. Hastings, and L. E. Berman, Phys. Rev. Lett. 67, 2850 (1991).
[4] Y. Podkovyrina et al., J. Phys.: Conf. Ser. 712, 012092 (2016).
[5] K. O. Kvashnina, Y. O. Kvashnin, S. M. Butorin, J. Electron. Spectrosc. Relat. Phenom. 194, 27 (2014).