Nuclear magnetic resonance methods were used to study the diffusion of F in a single crystal. The diffusivity at 315K could be described by:

D (cm2/s) = 7.1 x 10-4 exp[-11.5(kcal/mol)/RT]

Nuclear Magnetic Resonance Study of Fluorine Diffusion in Lanthanum Fluoride Single Crystals. A.G.Lundin, S.P.Gabuda, A.I.Lifshits: Fizika Tverdogo Tela, 1967, 9[1], 357-9