Conditions Extrêmes et Matériaux : Haute Température et Irradiation
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2015

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A-L.Rollet, H.Matsuura, C.Bessada, 'An in-situ spectroscopic study of the local structure of oxyfluoride melts :NMR insights into the speciation in molten LiF-LaF3-Li2O systems.', Dalton Trans. 44 522-529 (2015) doi:10.1039/c4dt00926f

The local structure of molten LaF3-LiF-Li2O has been investigated by measuring the 139La and 19F chemical shifts using High Temperature NMR spectroscopy. Li2O reacts completely with LaF3 to form LaOF compound at the solid state before the melting of the sample. LaOF is not completely dissolved in the fluoride melt and solid LaOF is observed on the 19F spectra for Li2O concentration above 10mol%. The analysis of the temperature and Li2O concentration dependences of the 139La and 19F chemical shifts suggests that several kinds of lanthanum oxyfluoride long-lived units (isolated LaOFx3−x and dimer La2OFy6−y) are present in the melt.