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Lutetium (III) fluoride is an inorganic chemical compound of lutetium from the group of fluorides
L 1665 (OTTO) Lutetium(III) fluoride, anhydrous, 99.99% Cas 13760-81-1 - used, for example, as a mixed crystal LiLu 1-x Nd x F 4 together with LiF and NdF 3 for scintillation counter.