XPS characterization of a PuGa-7 at. % alloy

Abstract

A δ-Pu(Ga-7 at. %) alloy has been characterized using x-ray photoelectron spectroscopy in the as-received condition, during sputter depth profiling through the surface oxide and following oxidation either by exposure to Langmuir quantities of oxygen or by oxidation from the residual gases in the ultrahigh vacuum environment. To enable quantitative analysis, we develop a procedure to separate the C 1s and Pu 5p1/2 peak intensities, which occur at the same binding energy. Sputter yields for the various oxides and alloys were calculated. The plutonium, oxygen, and gallium chemical state plots are presented for the oxides and alloy measured here.

Characterization of PuGa (1at%. Ga) Oxidation under Dry Oxygen Atmosphere Exposure

“…Recently, Donald et al [12] have evidenced the formation of a Ga-depleted layer beneath the oxide layer, and have attributed the existence of this layer to a Ga diffusion mechanism from the alloy to form Ga2O3 at the oxide/gas interface. However, this formation of Ga2O3 has been disputed by Roussel et al [13] based on XPS experiment results. Furthermore, according to the Reverse Monte Carlo analysis of EXAFS data performed by Ravat et al [14], Ga seems instead to be incorporated into Pu substitution sites of PuO2 lattice during oxidation.…”