A study was made of the permeation of H and D through Fe membranes, due to a pressure gradient, by measuring the pressure rise on the low-pressure side under steady-state conditions. The Fe used was of 3N5-purity and contained less than 0.003%C. At temperatures ranging from 360 to 560C, the ratio of the H and D permeabilities was given, with a 2% uncertainty, by:

ln [PH/PD] = 0.1024 + 149/T

The individual permeabilities obeyed:

H:     P (cm2/s atm½) = 2.99 x 10-3 exp[-8.45(kcal/mol)/RT]

D:     P (cm2/s atm½) = 2.70 x 10-3 exp[-8.75(kcal/mol)/RT]

O.D.Gonzalez: Transactions of the Metallurgical Society of AIME, 1967, 239[6], 929-30