Interactions of noble gas atoms with vacancies, interstitials and alloying titanium/chromium in vanadium

The presence of noble gas atoms has a large effect on the properties of nuclear materials, such as hardening and embrittlement. In this study, the clustering behavior of neon (Ne), argon (Ar) and krypton (Kr) atoms in vanadium and their interaction with vacancies/interstitials and alloying titanium/chromium (Ti/Cr) were investigated through first-principles calculations. Ne-Ne pairs exhibit attractive interactions with the binding energy of 0.75 eV, while most Ar-Ar and Kr-Kr pairs show repulsive interactions with the binding energies of −0.85 eV and −0.62 eV, respectively. Ne atoms tend to form interstitial clusters via the self-trapping effect and pre-existing vacancies further enhancing the cluster stability, whereas Ar and Kr clusters are less stable. Furthermore, the interactions of noble gas atoms with vacancy and self-interstitial atoms (SIAs) were determined to explore the effect of Ne on point defect behaviors. Ne can drive SIA migration and promote the recombination of SIAs and vacancies, while Ar and Kr primarily promote the diffusion and evolution of SIAs. Additionally, the alloying Ti can attract three noble gas atoms, thereby promoting their solution and retention, whereas Cr repels them. Finally, the effects of temperature and Ti concentration on the effective diffusivity of Ne, Ar and Kr were predicted using empirical formulas. This work deepens the understanding about the behavior of noble gas atoms and the interaction of point defects in vanadium alloys.