Migration in foils was measured at 0 to 100C by using an electrochemical time-lag method (table 160). A modified strain model indicated that the tetrahedral sites in body-centered cubic lattices had to be assumed to be stable positions for dissolved H. Elementary jumps, from one tetrahedral site to the next, passed directly through a tetrahedral plane. This model described qualitatively the experimental results, with respect to the order of the activation energies for H diffusion.

N.Boes, H.Züchner: Zeitschrift für Naturforschung A, 1976, 31[7], 760-8

Figure 36

Diffusivity of H in Ta