An ion-driven permeation method was used, in which the implantation of energetic ions was used instead of gaseous or electrochemical charging. The diffusion coefficients were deduced from the initial increase in permeation rate of an annealed specimen. It was found that the results could be described by:

D (m2/s) = 3.9 x 10-7 exp[-38.6(kJ/mol)/RT]

T.Tanabe, Y.Furuyama, N.Saitoh, S.Imoto: Transactions of the Japan Institute of Metals, 1987, 28[9], 706-14. See also: Journal of the Japan Institute of Metals, 1986, 50[8], 688-94