Thermodynamic properties of the O-U system. II - Critical assessment of the stability and composition range of the oxides UO 2+ x, U 4O 9- y and U 3O 8- z
The published data concerned with the determination of the composition ranges of uranium oxides, UO 2+ x, U 4O 9- y and U 3O 8- z, which have been determined using thermogravimetric, X-ray diffraction and electrochemical techniques are critically assessed. U 4O 9 and U 3O 8 have quite small domains of composition and the assessment of such data has carefully considered the uncertainties in the experimental determinations. In addition, the thermodynamic properties of U 4O 9 and U 3O 8, enthalpies of formation and transformation, entropies, and thermal capacities are analyzed and selected to build a primary data base for compounds.