The behaviors of He atoms and vacancies at TiO/V interface: A first-principles study

We study the behaviors of He atoms and vanadium vacancies at TiO/V interface by first-principles calculation to interpret the effects of TiO-precipitate on the He bubble nucleation. At TiO/V interface, He atom prefers to dissolve in the interstitial sites between TiO and adjacent V layer, and monovacancy tends to form in the adjacent V layer of TiO-precipitate. The TiO-precipitate promotes the formation of monovacancy and enhances the attractive interaction between He atom and monovacancy. Whether in monovacancy or multi-vacancy cluster, He atoms can be captured persistently in thermodynamics. In conclusion, TiO/V interface is a potential nucleation site in vanadium alloys for He bubbles. In addition, we also study the behaviors of He atom and mono vacancy in the vanadium crystal as a contrast. Our simulations provide a theoretical insight for further studying the formation of the He bubbles in vanadium alloys.

Automated summary

The TiO/V interface is a potential nucleation site for He bubbles in vanadium alloys, where TiO precipitation promotes the formation of monovacancies and enhances the attractive interaction between He atoms and monovacancies. Furthermore, He atoms can be persistently captured in both monovacancy and multi-vacancy clusters, suggesting a strong thermodynamic preference for He trapping at these defects.