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

Abstract 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 monovacancy 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.