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

To reveal the nature of the oxygen defects in actinide, lanthanide oxides, and their solid solutions, the relations between the molar ratio of oxygen to metal, O/M, and the oxygen potentials of these oxides in our previous studies were reviewed. These relations were then compared with those between O/M and the oxygen potentials in the literature, with reference to the phase relations and the constituent cationic valences and radii of these oxides. Consequently, we found 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 (e.g., fluorite-type, pyrochlore-type, and cubic sesquioxide-type).