Study on the phase separation behavior of (U,Nd)3O8 powder by high temperature oxidation

Several samples of (U 1− x Nd x ) 3 O 8 with different Nd content were prepared by different process. After high temperature oxidation, the final oxidized products were found to be a mixture of small particles Nd-rich (U 1− y Nd y )O 2+ v phases and large particles Nd-poor (U 1− z Nd z ) 3 O 8− w phases by XRD and SEM analysis. This study indicated that (U 1− x Nd x ) 3 O 8 powder formed a solid solution firstly at 1100 °C or high. The recrystallization of this solid solution happened and the RE-rich fluorite phase formed concurrently when the temperature began to decrease. The present work will provide more information to understand the oxidation behavior of rare-earth doped U 3 O 8 phase at high temperature.