1. Effect of short-range order on the solubility of actinides in Gd2Zr2O7.
- Author
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Zhao, Fengai, Tian, Ye, Teng, Zhen, and Hu, Shuanglin
- Subjects
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ACTINIDE elements , *SOLUBILITY , *PYROCHLORE , *CATIONS - Abstract
When exposed to severe environments, the short-range order in pyrochlores significantly influences their physicochemical properties. Using the DFT + U method, this study investigates the effect of short-range order on the solubility of actinides (An = Th, U, Np, Pu, Am, and Cm) in Gd 2 Zr 2 O 7 with distinct coordinated Gd and Zr sites. Our findings indicate that all the actinides under consideration are susceptible to being incorporated into the 7-fold Zr-site of quasi -weberite Gd 2 Zr 2 O 7. The weberite-like short-range order also favors immobilization of these actinides in the 6-fold Zr-site. The effect of the weberite-like motif on the solubility of actinides in the Gd-site of quasi -WB Gd 2 Zr 2 O 7 depends on the chemistry of the actinides. Furthermore, the short-range order results in a lower solution energy for An incorporation into the Gd and Zr sites of the quasi -weberite Gd 2 Zr 2 O 7 with cation antisites, thereby favoring An immobilization in a disordered environment. These results strongly demonstrate the importance of the short-range order on the solubility of actinides in disordered pyrochlores. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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