Can ternary polyhydrides surpass binary hydrides in Tc and reach room temperature?

Determine whether the superconducting critical temperature Tc in ternary hydrogen-rich polyhydrides synthesized under high pressure can exceed the Tc of binary hydrides and attain room-temperature values.

Background

The paper situates the search for room-temperature superconductivity within hydrogen-rich materials, noting that binary superhydrides such as H3S, YH6, and LaH10 already achieve high Tc under megabar pressures.

Despite extensive experimental efforts on ternary systems (e.g., La–Y–H, La–Ca–H, La–Al–H, La–Be–H, Y–S–H, and La–Ce–H), introducing a third element has often produced only modest changes in Tc, and in some cases reduced it, raising the overarching question of whether ternary compositions can truly outperform their binary counterparts.

The authors frame this as a central unresolved issue motivating their synthesis and characterization of La–Sc–H superhydrides, including observations suggestive of multiple superconducting phases and potential superconductivity above 0 °C.

References

The general and as yet unsolved problem of ternary superhydrides boils down to the question: "Can Tc in ternary polyhydrides be higher than in binary ones and reach room-temperature values?"

— Ternary superhydrides under pressure of Anderson's theorem: Near-record superconductivity in (La,Sc)H$_{12}$ (2408.07477 - Semenok et al., 14 Aug 2024) in Section 1. Introduction