抄録
The phase equilibrium of non-stoichiometric U3O8-x has been studied by thermogravi-metry in the range 765° ?? T ?? 995°C and 10-4 ?? Po2 ?? 1 atm. The results suggest the presence of six phases within the U3O8-x phase, separated by second (or higher) order transitions. The relative partial molar free energies, enthalpies and entropies within an each of the six phases, as well as the standard free energies, enthalpies and entropies for the phase changes are calculated and compared with previous works.