Sun Jian, Guo Xiaojing, Zhou Jing, Dai Jianxing, Song Sanzhao, Bao Hongliang, Lin Jian, Yu Haisheng, He Shangming, Jiang Feng, Long Dewu, Zhang Linjuan, Wang Jian Qiang
Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
The Education Ministry Key Laboratory of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Department of Chemistry and Chemical Engineering, Shanghai Normal University, Shanghai 200234, People's Republic of China.
J Synchrotron Radiat. 2019 Sep 1;26(Pt 5):1733-1741. doi: 10.1107/S1600577519009718. Epub 2019 Aug 20.
The microscopic structures of ThF-LiF and ThF-LiF-BeF molten salts have been systematically investigated by in situ high-temperature X-ray absorption fine-structure (XAFS) spectroscopy combined with molecular-dynamics (MD) simulations. The results reveal that the local structure of thorium ions was much more disordered in the molten state of the ThF-LiF-BeF salt than that in ThF-LiF, implying that the Th and F ions were exchanged more frequently in the presence of Be ions. The structures of medium-range-ordered coordination shells (such as Th-F and Th-Th) have been emphasized by experimental and theoretical XAFS analysis, and they play a significant role in transport properties. Using MD simulations, the bonding properties in the molten ThF-LiF and ThF-LiF-BeF mixtures were evaluated, confirming the above conclusion. This research is, to the best of our knowledge, the first systematic study on the ThF-LiF-BeF molten salt via quantitative in situ XAFS analysis and MD simulations.
通过原位高温X射线吸收精细结构（XAFS）光谱结合分子动力学（MD）模拟，对ThF-LiF和ThF-LiF-BeF熔盐的微观结构进行了系统研究。结果表明，在ThF-LiF-BeF盐的熔融状态下，钍离子的局部结构比在ThF-LiF中更加无序，这意味着在铍离子存在的情况下，钍和氟离子的交换更为频繁。通过实验和理论XAFS分析强调了中程有序配位壳层（如Th-F和Th-Th）的结构，它们在传输性质中起着重要作用。利用MD模拟评估了熔融ThF-LiF和ThF-LiF-BeF混合物中的键合性质，证实了上述结论。据我们所知，这项研究是首次通过定量原位XAFS分析和MD模拟对ThF-LiF-BeF熔盐进行的系统研究。
