{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c94674ef10128371625faf5791d8fb6d4f60be9d50c054f87c7f27d5b65c8bfc","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["2f591cb938004a94308b52357a74534a2c85e53a87b747a64c14bdcca463ae45","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"a92eeac3c74560e9506c719ac40c64670594fe42122aeffe2adfbfd8bb23e0d6","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.hydrides.la-sc-h-room-temperature","kind":"well-posed","literature_status":"open","n":"2","parents":[],"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.","posed_since":"2025","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 $\\mathrm{LaSc_2H_{24}}$, 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 $\\mathrm{LaSc_2H_{24}}$. An answer is independent replication with magnetic data, or failure to reproduce under the stated synthesis.","problem_ref":"2f591cb938004a94308b52357a74534a2c85e53a87b747a64c14bdcca463ae45","references":"","settled_by":"Independent synthesis of $\\mathrm{LaSc_2H_{24}}$ with resistive and magnetic transitions above 270 K at a calibrated pressure, plus a deuterium isotope measurement.","status_note":"Reported in September 2025 by a single group; independent replication had not been confirmed as of this entry (October 2026).","title":"Is 298 K superconductivity in compressed La-Sc-H 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