The H flux (J) was measured through multilayer membranes of Pd and Pd–Al alloy prepared by internal oxidation of the alloy. A plot of 1/J against thickness of the Pd layers, 2dPd, was linear for a series of different 2dPd values. This justified assumptions of the model used to derive the relation between 1/J and 2dPd. DH for Pd and the alloy could be obtained from intercepts of the plot using known pH2–H content isotherms. Since it was shown that internal oxidation led to more reproducible and poison-resistant Pd based membranes, the multilayer technique was an alternate way to obtain DH for Pd alloys.

H Diffusion through Partially Internally Oxidized Pd-Alloy Membranes. D.Wang, T.B.Flanagan, K.L.Shanahan: Scripta Materialia, 2006, 54[7], 1317-20