Resonant x-ray spectroscopy of uranium intermetallics at the M4,5 edges of uranium

We present resonant x-ray emission spectroscopic data from the uranium intermetallics UPd3, USb, USn3, and URu2Si2 at the M4,5 edges of uranium, and we compare the data to those from the well-localized 5f2 semiconductor UO2. The technique is especially sensitive to any oxidation of the surface, and this was found on the USb sample, thus preventing a good comparison with a material known to be 5f3. We have found a small energy shift between UO2 and UPd3, both known to have localized 5f2 configurations, which we ascribe to the effect of conduction electrons in UPd3. The spectra from UPd3 and URu2Si2 are similar, strongly suggesting a predominant 5f2 configuration for URu2Si2. The valence-band resonant inelastic x-ray scattering provides information on the U P3 transitions (at about 18 eV) between the U 5f and U 6p states, as well as transitions of between 3 and 7 eV from the valence band into the unoccupied 5f states. These transitions are primarily involving mixed ligand states (O 2p or Pd,Ru 4d) and U 5f states. Calculations are able to reproduce both of these low-energy transitions reasonably well.

KVASHNINA K.;  WALKER H.C.;  MAGNANI Nicola;  LANDER G. H.;  CACIUFFO Roberto; 

2017-08-01

AMER PHYSICAL SOC

JRC105902

2469-9950,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC105902,   

10.1103/PhysRevB.95.245103,