Effect of carbon on behavior of helium in vanadium: A first-principles investigation

By using the first-principles calculations, we studied the effect of carbon (C) on the behaviors of helium (He) in vanadium (V). The results show that C can effectively reduce the solubility of He in bulk V. Compared with defect-free V bulk, the C-vac complex reduces the charge density around it, which makes it act as a trapping center and promotes He nucleation. The maximum number of He atoms trapped by the C-vac complex is five. Furthermore, the interaction between He and the C-vac complex is slightly stronger than that in a C-free vacancy, which indicates that C could increase the trapping ability of vacancy to He atom. Based on the above results, we conclude that C has a certain influence on the dissolution and the trapping behaviors of He in V.