SYNTHESIS AND CHARACTERIZATION OF MIXED-V ALENCE URANIUM ORTHOPHOSPHATE - U(UO2)(PO4)(2)

A new mixed valence uranium orthophosphate, U(UO2)(PO4)(2), has been s ynthetized through dry and wet chemical processes. Results obtained by means of X-ray diffraction, ultraviolet-visible absorption, infrared, Raman and XPS spectroscopies show that this uranium orthophosphate pr epared through both ways does not correspond to those previously menti oned in the litterature: U-3(PO4)(4) and U2O3P2O7. The presence of the molecular ion UO22+ has been shown on the obtained spectra whereas th e diphosphate group P2O74- is absent according to the infrared spectru m and to the crystallographic studies.