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