First-Principles Molecular Dynamics Simulation of a Liquid Li-Sn as a Plasma-Facing Component*

Liquid metals, with inherent disorder, have long been suggested as plasma-facing components (PFC) in fusion reactors due to their imperviousness to mechanical damage, thereby allowing for a self-healing and self-replenishing surface. The most promising candidates for liquid PFCs are lithium (Li) and the lithium-tin alloys (Li₃₀Sn₇₀ and Li₂₀Sn₈₀) due to their low melting points and evaporation rates. Although liquid Li properties have been studied extensively, further research into the behavior of LiSn is needed.

We present results of first-principles molecular dynamics simulations of liquid Li₃₀Sn₇₀ and its interaction with various concentrations of deuterium from the melting point up to 970 K. Static and dynamic properties such as pair distribution functions, diffusion coefficients, and viscosities are evaluated. Moreover, deuterium retention in the liquid Li-Sn alloy is compared to that of pure liquid Li. Overall, we provide insight into the atomic-scale behavior of Li₃₀Sn₇₀, which will be useful for further research into PFCs for fusion reactors.