Diffusion of hydrogen in disordered BCC VyTa1-y-H (D) alloys : An NMR study

Times of nuclear spin-lattice relaxation of hydrogen isotopes 1 H and 2 D in a disordered bcc system V y Ta 1 -yHx (D x ) (0.25 ≤y≤ 0.85, 0.07 ≤ x≤0.4) were measured in a temperature range of 11-430 K. From an analysis of relaxation data using the model with a Gaussian distribution of activation energies, the parameters of H (D) diffusion were determined, The dependence of the average activation energy of diffusion E a on the hydrogen concentration is different in different ranges of y. Comparison of the parameters of diffusion of H and D in hydrided and deuterided samples of close compositions shows a distinct isotope effect on the activation energy of their diffusion: E a C > E a H .