Effect of neon on the hydrogen behaviors in tungsten: A first-principles study

Seeding the impurity elements in W can affect the H behaviors. The effect of Ne on H behaviors in W bulk and W (110) surface has been investigated with the first-principles density functional theory (DFT) calculations in the present paper. It is found that the interactions between the interstitial Ne and H are attractive in bulk W. Ne atom can reduce the binding energies for H in the vacancy and divacancy, and the binding energies decrease linearly with the ratio of Ne and vacancy. In the W (110) surface without vacancy, the threefold hollow site is the most preferable site for H adsorption; Ne atom cannot be adsorbed on the W surface and in the subsurface because of the weak interaction. The substitutional Ne in subsurface can impede H absorption, and increase the diffusion barrier for H from the surface into subsurface.