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Title: Is 298 K superconductivity in compressed La-Sc-H reproducible
Plain: A 2025 report claims that a hydrogen-rich compound of lanthanum and scandium superconducts up to about room temperature when squeezed to about 2.5 million atmospheres; independent confirmation is required.
Precise: Song et al. (arXiv 2510.01273, 2025) report onset $T_c = 271\ \text{to}\ 298\,\mathrm{K}$ at $1.95\ \text{to}\ 2.66\,\mathrm{Mbar}$ in hexagonal LaSc2H24, synthesized by laser heating La-Sc alloy with ammonia borane in diamond anvil cells, with zero resistance, field suppression of $T_c$ and synchrotron diffraction. Determine whether independent groups reproduce $T_c$ above $270\,\mathrm{K}$ in the same structure, and whether magnetic signatures (flux expulsion, trapped flux) and the isotope coefficient agree with Eliashberg predictions for LaSc2H24. An answer is independent replication with magnetic data, or failure to reproduce under the stated synthesis.
Settled by: Independent synthesis of LaSc2H24 with resistive and magnetic transitions above 270 K at a calibrated pressure, plus a deuterium isotope measurement.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: open
Status note: Reported in September 2025 by a single group; independent replication had not been confirmed as of this entry (October 2026).
Posed since: 2025