Hydrogen diffusion in Nb1−y Vy alloys

Tracer diffusion coefficients D_t of hydrogen in niobium and some Nb_1−y V_yH_x alloys have been measured and are compared with chemical diffusion coefficients D_c from the literature. Nuclear magnetic resonance pulsed field gradient techniques were used to measure D_t. Comparison of the two diffusion coefficients is made taking into consideration the thermodynamic factor $\text{(k}{}_{\mathrm{B}}\text{T)}{}^{\mathrm{-1}}\text{[}\text{∂μ}\text{∂(ln x}\text{)]}$ which is obtained from pressure-composition isotherms for the alloys. The comparisons indicate satisfactory agreement between the two measures of the diffusion coefficient.