The recovery of excess D which was dissolved in Ni was studied by means of liquid-H quenching and electrical resistivity measurements. The diffusion of D was found to be described by:

D (cm2/s) = 3.18 x 10-3 exp[-9220/RT]

at between 220 and 340K. A study of these and other results showed that the pre-exponential factor for H diffusion was lower than that for D diffusion. The same relationship was true of the activation energies.

K.Yamakawa: Journal of the Physical Society of Japan, 1979, 47[1], 114-21