The diffusion of hydrogen at low temperatures in PdErH ternary solutions

An electrolytic technique has been used to measure the temperature variation of the diffusivity of hydrogen in PdEr solid solutions containing up to 8 at.% Er. The diffusivities were measured in the temperature range 270–340 K. The diffusion data for a given PdEr binary solvent conform to the Arrhenius representation. However the apparent activation energies Qa exhibit a non-linear variation with Er content. The Qa value show an initial increase with Er content and then a decrease after a maximum at ∼ 5 at.% Er. This behavior has been interpreted in terms of a statistical model based upon classical jump theory.