Gorsky-effect experiments were carried out on monocrystalline alpha'-PdHx alloys, with 0.56 < x < 0.74, between 300 and 600K using a capacitance method for strain measurement. The long-range diffusion coefficients derived from the anelastic relaxation time were consistent with previous results for similar temperature and/or concentration regimes. Arrhenius plots of the reduced or tracer-diffusion coefficient indicated activation energies which were no more than 15% larger than the values found for dilute alpha-phase PdHx alloys. The concentration dependence of the tracer diffusivity varied more rapidly than 1-x. This deviation from a simple site-blocking model was an indication of the existence of hydrogen-hydrogen cooperative effects involving a short-range repulsive interaction between the protons.

Gorsky Effect in Concentrated α'-PdHx. A.H.Verbruggen, C.W.Hagen, R.Griessen: Journal of Physics F, 1984, 14[6], 1431

Figure 29

Diffusivity of H in Pd