A steady-state flow technique was used to measure the effective charge number and permeability of H and D. It was found that, for temperatures of 485 to 720C and pressures of 220 to 750torr, the effective charge number was a constant. The interstitial impurity migrated in the direction of the electron wind, with ZH* = -6.8e and ZD* = -18e. The Z* values were of the same order as in self-electromigration, but the size of the isotope effect was surprising. In order to x determine the effective charge number, it was necessary to measure the permeability. The permeability obeyed the equations:

D:     P (cm2/s atm½) = 2.39 exp[-14.4(kcal/mol)/RT]

H:     P (cm2/s atm½) = 2.86 exp[-14.2(kcal/mol)/RT]

The isotope effect ratio, PH/PD = 1.25, was smaller than the expected value.

Electromigration and Permeation of Hydrogen and Deuterium in Silver. R.E.Einziger, H.B.Huntington: Journal of the Physics and Chemistry of Solids, 1974, 35[12], 1563-73