U3O8 high energy x-ray photoelectron spectroscopy reference spectra generated with Ga Kα x-ray source

High energy x-ray photoelectron spectroscopy (HAXPES) measurements were carried out using a Scienta Omicron HAXPES instrument to provide reference spectra for depleted triuranium octoxide. Triuranium octoxide, as confirmed by x-ray diffraction, was synthesized by calcination of uranyl chloride at 1000 °C. The material was fixed on a double-sided carbon tape for the analysis with charge control measures in place. The expanded energy range, using a Ga Kα x-ray source, presents core-level photoelectrons not observed in traditional XPS. Included also is the region associated with MNN x-ray-induced Auger transitions, which can only be observed at energies achievable with HAXPES instrumentation. These reference spectra build on previous work by the authors on uranium dioxide, expanding the knowledge of the uranium/oxygen system by HAXPES and XPS analysis.