A previously developed approach to the description of H diffusion in disordered crystalline alloys was generalized to the case of amorphous states. Expressions were obtained for the chemical diffusivity of H in amorphous alloys with short-range crystalline order of face-centered cubic lattice type. The diffusivity was found to be related to a structural characteristic of the disordered material. This was the mean-square static displacement of atoms in the vicinity of a void, which could be expressed in terms of the atomic radial pair distribution function. Because of the crystalline disorder, the diffusivity depended strongly upon the H concentration. Contrary to the case of perfect crystals, this dependence was linear. The present model adequately described the temperature dependence of the H diffusivity in amorphous alloys. Under certain conditions, the expressions for the diffusivity became identical to those derived by Kirchheim.

On the Theory of Hydrogen Diffusion in Amorphous Metals and Alloys. V.V.Kondratev, A.V.Gapontsev: Physics of Metals and Metallography, 1999, 87[5], 363-9