The diffusion of H in the C15 compound was measured, at temperatures ranging from 230 to 450K, by using pulsed-field gradient nuclear magnetic resonance techniques. The temperature dependence of the diffusivity could be described by:

D (m2/s) = 1.8 x 10-8 exp[-0.22(eV)/kT]

These results were in good agreement with values which had been estimated from proton spin-lattice relaxation rate measurements of the same sample. As a result, it was possible to distinguish between long-range diffusion and localized motion.

W.Renz, G.Majer, A.V.Skripov: Journal of Alloys and Compounds, 1995, 224[1], 127-9