Nuclear Materials and Energy (Sep 2024)
Effect of electronic excitations on hydrogen behavior in tungsten
Abstract
The interaction between ions should be greatly modified under electronic excitation states, subsequently altering the interactions between materials. We perform a series of first-principles calculations to predict the solution and diffusion behaviors of interstitial hydrogen (H) in tungsten (W) under various electronic excitations. Qualitatively, the solution, diffusion, and trapping behaviors of H in W under various electronic excitation states are basically consistent with those in the ground state. However, it can be found that the solution energy and the migration energy barrier of H decreases as increasing the electronic temperature of system. The Pearson correlation coefficient study shows that there exists a perfect negative correlation between the lattice constant of W and H solution energy induced by lattice distortion. Besides, electronic excitations also make the binding energy of multiple H atoms decrease. That is, when the same number of H atoms are added to the vacancy, the binding energy decreases with increasing the electronic temperature of system. Based on these calculation results, we can infer that electronic excitations make dissolved H atoms more active in W system. This may, to some extent, allow dissolved H to migrate around and not aggregate so easily, thus reducing the production of H bubbles. Therefore, in quantitative terms, the electronic excited states have a certain effect on the H behavior in W.