The diffusion of H in α-Pd at room temperature was studied by using a galvanostatic technique. Single-transient and multiple-transient H-charging was carried out using a range of charging currents and specimen thicknesses. A mathematical description of multiple-transient charging was based upon the general solution for diffusion. The diffusivity at 23C was equal to 3.4 x 10-7cm2/s. This value was in excellent agreement with the results of Gorsky-effect measurements. The results demonstrated that bulk H diffusion was the rate-controlling process, and that the H-flux boundary conditions, which were assumed in mathematical analyses, were satisfied by the galvanostatic technique.

Hydrogen Diffusion in Palladium by Galvanostatic Charging. J.G.Early: Acta Metallurgica, 1978, 26[8], 1215-23

Figure 28

Diffusivity of H in α-Pd