Deuterium diffusion in proton conductors La0.9Sr0.1ScO3 -δ and BaZr0.9Y0.1O3 -δ at room temperature

• A new technique was developed for measuring diffusion coefficients in solids.
• The technique is intended for systems with very fast deuterium diffusion.
• “Online regime” comprising ion implantation, diffusion annealing and NRA is used.
• Diffusion data for deuterium in proton conductors at room temperature were obtained.

Room-temperature measurements of diffusion coefficients for deuterium in proton conductors La0.9Sr0.1ScO3 -δ and BaZr0.9Y0.1O3 -δ which contain dissolved H2O vapor have been performed. The concentration of oxygen structure vacancies in oxides after treatment in vapor was close to zero. A diffusion source of deuterium was created by ion implantation; measurement of the concentration–distance distribution of deuterium in samples was performed in situ during implantation. The NRA technique and 2H(d,p)3H reaction at an energy of the incident beam of 650 keV were used. For the initial and boundary conditions of the diffusion problem which were realized in the work, a solution of the inhomogeneous Fick equation was obtained. Using the technique developed, measurements of the diffusion coefficients for hydrogen in proton conductors were for the first time performed directly. For the BaZr0.9Y0.1O3 -δ oxide, the directly gained values of diffusion coefficients agree rather well with those obtained from the proton conductivity with the use of Nernst–Einstein equation.