The diffusion of hydrogen through copper

At temperatures higher than about 400°C, several observers have determined the rates of diffusion of hydrogen through copper, and only recently has a paper by Smithells and Ransley appeared, giving measurements on diffusion as low as 225°C. Sieverts, Deming and Hendricks, and Lombard have shown that the copper tubes and plates used in the experiments at high temperatures tend to crystallize and become fissured, so that the measurements are of little value. The adsorption of hydrogen by copper has been thoroughly studied over a large temperature range. Ward has shown that, at low temperatures, the immediate initial adsorption is followed by a slow solution of the hydrogen in the copper. Solution increases very rapidly with temperature, and above 160°C is so large and so rapid that the initial adsorption cannot be accurately determined.