The migration of H in high-purity material was studied by using the Gorsky-effect anelastic technique. The observed H diffusivities depended upon the concentrations of trapping sites such as dislocations and O atoms. At low interstitial solute levels and low dislocation densities (104/cm2), the activation energy was 0.080eV. As the number of O trapping sites increased, the activation energy increased to a value of 0.096eV at 0.23at%O (table 93). The introduction of dislocation trapping sites by cold-rolling (10% reduction of area) increased the activation energy to 0.093eV. High activation energies were also observed in specimens that contained high H concentrations after extensive hydride precipitation had occurred. This was consistent with the large amount of plastic deformation that occurred when such hydrides were precipitating.

On Gorsky Effect Measurements of Hydrogen Diffusion in Niobium. G.Matusiewicz, R.Booker, J.Keiser, H.K.Birnbaum: Scripta Metallurgica, 1974, 8[12], 1419-25