DIFFUSION OF HYDROGEN IN DISORDERED NB1-YVY ALLOYS

Macroscopic diffusion coefficients D* have been measured as a function of temperature ((273 divided-by 550)K) in various Nb(1-y)V(y) alloys and at 300 K as a function of hydrogen concentration (c = 0.001 divided-by 0.033) in Nb0.90V0.10. Model calculations, using site-dependent (activation) energies show excellent agreement between experimental and calculated macroscopic diffusion coefficients. The highly nonlinear concentration dependence predicted by the model in Nb0.90V0.10 at 300 K, and not observed before in any crystalline alloy, is confirmed experimentally.