XPS study of neptunium and plutonium doped iron-bearing and iron-free sodium-aluminum-phosphate glasses

The iron-free and iron-bearing (Np, Pu)-containing sodium-aluminum-phosphate glass samples were studied by X-Ray photoelectron spectroscopy. Oxidation states of neptunium, plutonium and iron, and elemental composition of the surfaces of the samples studied were determined. In both iron-free and iron-bearing glasses Np is present predominantly as Np(V) on the surface and Np(IV) in the bulk. Pu(III) dominates over Pu(IV)/(V) in the iron-free glass while oxidized forms of Pu prevail in the iron-bearing glass.