50 / 2026-03-23 11:02:40

Multinary Hydride superconductors Under High Pressure

high pressure; hydride; superconductivity

高压物理与材料科学 > 静高压物理与材料科学

The pursuit of high-temperature and even room-temperature superconductors has remained a central focus for scientists. In recent years, researchers have proposed the academic concept of searching for metallic hydrogen and high-temperature superconductors in hydrides. Due to the presence of non-hydrogen elements, which exert a chemical pre-compression effect on the hydrogen sublattice, hydrogen-rich compounds can achieve metallization and superconducting transitions at lower pressures. Featuring high Debye temperatures and strong electron-phonon coupling, these compounds are potential high-temperature superconductors. Experimentally confirmed high-temperature superconductors among hydrides currently fall into two main categories: the first is covalent hydrides represented by H₃S, and the second is cage-like hydrides represented by LaH₁₀. Both types exhibit superconducting transition temperature (T_c) exceeding 200 K under high pressure, sparking a surge of research interest in hydride superconductors.

       

         Introducing multiple non-hydrogen elements to modulate the hydrogen lattice and form multinary hydrides could further enhance superconducting performance or reduce the required synthesis pressure. This report primarily introduces newly discovered high-temperature superconductors among multinary hydrides. For example, using a La-Ce solid solution alloy as a precursor, the ternary hydride P6₃/mmc-(La,Ce)H₉ was successfully synthesized under high-temperature and high-pressure conditions. This compound exhibits a T_c of 180 K at 100 GPa and a critical magnetic field of 235 T. This system is currently the highest-temperature superconducting alloy-type hydrogen-rich compound known at pressures below one million atmospheres. Employing a similar approach, by introducing an appropriate amount of aluminum atoms, the P6₃/mmc-LaH₁₀ phase, which was theoretically predicted to stabilize only above 420 GPa, was successfully stabilized at 146 GPa. The synthesized P6₃/mmc-(La,Al)H₁₀ exhibits a maximum T_c of 223 K. This series of research has invigorated experimental exploration of multinary hydride superconductors and provides new directions and ideas for the study of room-temperature superconductors.