XAFS analyses of molten metal fluorides

• Published in: Journal of fluorine chemistry Vol. 130; no. 1; pp. 53 - 60
• Main Authors: Matsuura, Haruaki, Watanabe, Sou, Akatsuka, Hiroshi, Okamoto, Yoshihiro, Adya, Ashok K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2009
• Subjects: Alkaline-earth metal fluoride; Lead fluoride; Local structure analysis; Molten metal fluoride; Molten salt reactor; Pyrochemical treatment; Rare earth metal fluoride; Synchrotron radiation; X-ray absorption fine structure; Pyrochemical treatment; Molten metal fluoride; Rare earth metal fluoride; Local structure analysis; Alkaline-earth metal fluoride; X-ray absorption fine structure; Molten salt reactor; Synchrotron radiation; Lead fluoride
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2008.07.012

The local structural parameters of molten divalent and trivalent fluorides and their mixtures obtained by X-ray absorption fine structure are widely discussed. ▪ X-ray absorption fine structure studies of molten metal fluorides containing the materials related to nuclear engineering are intensively summarized. By using XAFS spectra data of divalent and trivalent cation metal fluorides in molten state which have been collected by authors’ group for a few years, local structure have been extracted and discussed systematically in conjunction with other spectroscopic studies and numerical calculations. In molten divalent fluorides, tetrahedral coordination of fluorides around a cation is predominant. In the case of pure molten trivalent fluorides, structure with more than 6-coordination has been suggested in some cases, but octahedral coordination structure is much stabilized at heavier rare earth metal fluorides. By mixing with alkali metal fluorides, it is a general trend that inter-ionic distances keep constant, but coordination number of fluorides decreases. In experimental chapter, all the details of sample preparation, furnace installation, X-ray optics setups and data analyses procedures are explained. Finally, future expectations of XAFS technique are also suggested.