Oxygen defects of actinide, lanthanide oxides, and their solid solutions

Otobe, Haruyoshi  

The chemical properties (ex. atomic diffusion), the thermal properties (ex. melting point and thermal diffusivity) and the mechanical properties of oxide fuels are significantly dependent on the oxygen defects of the oxide fuels. For the first step to specify the oxygen defects of oxide fuels, we have tried the thermodynamic approaches to the oxygen defects by comparing the relations between the molar ratio of oxygen to metal (O/M) and the oxygen potentials of Pu, Am, Cm, Ce oxides and several solid solutions including Zr and Np dioxides. Consequently, we have found the consistent properties in the relations between O/M and the oxygen potentials of actinide, lanthanide oxides and their solid solutions, in addition to the dependence of the relations on the crystal structures.