Abstract

Liquid metals are being explored actively as candidates for plasma-facing components (PFCs) in fusion reactors. Recently, Li–Sn alloys have appeared as promising alternatives that could overcome some of the challenges faced by the well-studied liquid Li system, namely, a vapor pressure that limits the operating temperature and a high hydrogen isotope retention. However, only scarce data (experimental or theoretical) are available concerning the performance of Li–Sn alloys, specifically only for the compositions of Li₃₀Sn₇₀ and Li₂₀Sn₈₀, related to their bonding and retention of deuterium (D). Here, we present a comprehensive, first-principles molecular-dynamics study of static and dynamic properties of liquid Li₃₀Sn₇₀ at various D concentrations. We observe the formation of D₂ gas bubbles for β in Li₃₀Sn₇₀D β greater than 22.5 along with Li segregation towards D₂ bubbles. To understand the effect of Sn addition on D retention in Li–Sn alloys, we perform a thermodynamic evaluation of maximum D retention in Li-rich Li–Sn alloys. Overall, this work will provide useful data and guidance in the development of Li–Sn PFCs in fusion reactors.