Diffusion behaviors of hydrogen isotopes in niobium from first-principles

We investigate diffusion behaviors of hydrogen(H),deuterium(D),and tritium(T) in bulk niobium(Nb) using first-principles method.The diffusion energy barrier with quantum-correction has been calculated to be 0.12 eV,which is in good agreement with the experimental value of ～0.106 eV.According to diffusion theory presented by Wert and Zener,the diffusion pre-exponential factors of H,D,and T are shown to be 7.74×10-8m 2 s-1,5.47×10-8 m 2 s-1 and 4.48×10-8 m 2 s-1,respectively.These results are also in quantitative agreement with the corresponding experimental values.