Long-Range Diffusion of Hydrogen in Amorphous Cu₅₀Ti₅₀

Abstract
The hydrogen Gorsky effects (HGE) measurements were carried out in amorphous Cu₅₀Ti₅₀, for which the data for the hydrogen Snoek peak (HSP) have been compiled. In the hydrogen concentration, C_H, range below 1 at.%, the hydrogen diffusion process changes over from the short circuit mode to the detrapping mode with increasing C_H and (λ)² is much smaller than (trλ)², where λ is the strain tensor around a hydrogen atom. For C_H>1 at.%, the hydrogen diffusion proceeds by the detrapping mode. The whole hydrogen atoms contribute to the HGE although only hydrogen atoms sitting on the sites with G being nearly equal to µ contribute to the HSP, where G is the site energy and µ the chemical potential of hydrogen atoms. The results are expected as a dispersion in G is much larger than thermal energies and the nearest neighbor blocking for hydrogen occupation is the case. (λ)² is much larger than , suggesting that one or two of (trλ)², λ₁,λ₂ and λ₃ is (are) negative for C_H>1 at.%.