The diffusion of hydrogen in copper‐palladium alloys was studied (table 23) by exploiting the dependence of electrical resistivity upon hydrogen concentration. At 25C, the diffusion coefficient in the range of 0 to 58at%Cu was relatively insensitive to alloy composition but was extremely sensitive to the α‐β phase-change: it increased by two orders of magnitude to become 5 x 10-5cm2/s when the crystal structure of the alloy system changed from face‐centered cubic to ordered body‐centered cubic. Measurements performed at 130C indicated that this large increase was due to a factor-of-three decrease in the activation energy for diffusion. The ratio of the diffusion coefficient for hydrogen, to that for deuterium, in the body‐centered cubic alloy was found to be approximately 1.5.

Diffusion of Hydrogen in Copper-Palladium Alloys. J.Piper: Journal of Applied Physics, 1966, 37, 715

Table 22

Parameters for H Permeation in Cu3Au