Chemical State of Complex Uranium Oxides

The chemical state of complex uranium oxides

Uranium oxides are fascinating materials not only owing to their technological significance in nuclear fuel applications [1] but also with respect to their dynamical properties [2], valence orbital configuration [3] and elementary excitations [4]. Understanding of the electronic, magnetic and crystal structural properties of uranium dioxide (UO2) was advanced significantly [5,6] after establish...

Uranium extraction from laboratory-synthesized, uranium-doped hydrous ferric oxides.

The extractability of uranium (U) from synthetic uranium-hydrous ferric oxide (HFO) coprecipitates has been shown to decrease as a function of mineral ripening, consistent with the hypothesis that the ripening process will decrease uranium lability. To evaluate this process, three HFO suspensions were coprecipitated with uranyl (UO2(2+)) and maintained at pH 7.0 +/- 0.1. Uranyl was added to the...

Chemical Thermodynamics of Uranium

Degradation of polyethylene oxides during irradiation with uranium ions

This project focuses on polyepoxides used in glass fiber reinforced polymer (GFRP) compounds, to be applied as insulators or structure-support materials for magnets of the future FAIR facility. As such, polyepoxides have to withstand high radiation levels of X-rays, gammas, neutrons, protons, and heavier particles [1]. Radiation hardness tests are important in order to estimate lifetimes and pe...

Uranium oxides investigated by X-ray absorption and emission spectroscopies

X-ray absorption and resonant X-ray emission measurements at the O 1s edge of the uranium oxides UO2, U3O8 and UO3 are presented. The spectral shapes of the O Kα X-ray emission spectra of UO3 exhibit significant excitation energy dependence, from an asymmetric to a symmetric form, which differs from those of UO2 and U3O8. This energy dependence is attributed to a significant difference in the o...