First-principles calculations of transition elements interaction with hydrogen in vanadium

Abstract

We performed systematic first-principles calculations to investigate the interactions of 26 transition elements (TEs) with hydrogen (H) and vacancy in vanadium (V). In the presence of 26 substitutional solute elements (Sc,Ti,Mn,Cr,Co,Fe,Cu,Ni,Y,Zr,Mo,Nb,Rh,Ru,Pd,Tc,Ag,La,Hf,W,Ta,Os,Re,Pt,Ir,Au), H still prefers to occupy the tetrahedral interstitial sites. H is unstable for solute elements at the nearest octahedral interstitial sites except for Ni and Cu. Then we calculated the binding energies of TEs and H with their distances. H atoms are attractive with early three 3d/4d/5d TEs (Sc/Ti/Y/Zr/La/Hf) and repulsive with other TEs. And we predicted the effect of solid solution elements on H diffusivity, Sc/Y/Zr/La/Hf can significantly reduce the effective diffusivity of H, while other elements have little effect on it. In addition, most of TEs can stabilize TE-vacancy-H clusters, the interactions of all TE-vacancy-H clusters are attractive and decrease with the increase of atomic number in the same period. In the case of pre-existing TE-vacancy complex defects, most of TEs can reduce the binding strength of vacancy to H. These results deepened the understanding of the TEs-H interactions and H retention in V alloys under irradiation.