Open AccessInvestigation of the local structure of molten ThF 4 –LiF and ThF 4 –LiF–BeF 2 mixtures by high‐temperature X‐ray absorption spectroscopy and molecular‐dynamics simulation
Author(s) -
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
Publication year - 2019
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577519009718
Subject(s) - x ray absorption fine structure , molten salt , chemistry , ion , absorption (acoustics) , spectroscopy , absorption spectroscopy , molecular dynamics , coordination number , molecule , extended x ray absorption fine structure , salt (chemistry) , analytical chemistry (journal) , crystallography , inorganic chemistry , materials science , computational chemistry , organic chemistry , physics , quantum mechanics , composite material
The microscopic structures of ThF 4 –LiF and ThF 4 –LiF–BeF 2 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 4 –LiF–BeF 2 salt than that in ThF 4 –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 2nd 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 4 –LiF and ThF 4 –LiF–BeF 2 mixtures were evaluated, confirming the above conclusion. This research is, to the best of our knowledge, the first systematic study on the ThF 4 –LiF–BeF 2 molten salt via quantitative in situ XAFS analysis and MD simulations.