Migration in foils was measured at 0 to 100C by using an electrochemical time-lag method (table 88). 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 in these metals.
N.Boes, H.Züchner: Zeitschrift für Naturforschung A, 1976, 31[7], 760-8
Table 87
Parameters for D and H Diffusion in Nb
Isotope | Temperature (K) | Do (cm2/s) | E (eV) |
D | 120-600 | 5.4 x 10-4 | 0.129 |
H | 120-300 | 9.0 x 10-5 | 0.068 |
H | 300-600 | 5.0 x 10-4 | 0.106 |