Diffusion in 3N5-purity material was determined by using gas-phase, ion and electrochemical permeation techniques at 240 to 970K. The data could be described by:

D (cm2/s) = 3.35 x 10-4 exp[-0.035(eV)/kT]

The results indicated that, although the H diffusivity could be expressed by an equation of Arrhenius type, the isotope dependence was not of classical type within the above temperature range.

Y.Hayashi, H.Hagi, A.Tahara: Zeitschrift für Physikalische Chemie, 1989, 164[1], 815-20