The pressure, and lattice parameter, dependences of H diffusion in NbH0.002 were studied at 187K by using neutron spectroscopic techniques. The diffusivity at 187K and 1bar was equal to 8.6 x 10-7cm2/s. It was found that a pressure of 5kbar reduced the lattice parameter by about 0.1% and decreased the diffusion coefficient by about 3.4%. This pressure dependence was much smaller than that of H diffusion in Pd at room temperature.
U.Stuhr, H.Wipf, C.Vettler, H.R.Schober: Solid State Communications, 1991, 80[12], 987-9
Table 83
Parameters for H and D Diffusion in Nb at 0 to 100C
Isotope | Do (cm2/s) | E (kcal/g-atom) | D25C (cm2/s) |
H | 3.6 x 10-4 | 2.5 | 5.2 x 10-6 |
D | 5.0 x 10-4 | 2.8 | 4.5 x 10-6 |