{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T02:23:15Z","timestamp":1791598995142,"version":"4.3.4"},"reference-count":39,"publisher":"American Chemical Society (ACS)","issue":"32","license":[{"start":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:00:00Z","timestamp":1785542400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:00:00Z","timestamp":1785542400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:00:00Z","timestamp":1785542400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/501100003787","name":"Natural Science Foundation of Hebei Province","doi-asserted-by":"publisher","award":["E2025203149"],"award-info":[{"award-number":["E2025203149"]}],"id":[{"id":"10.13039\/501100003787","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003787","name":"Natural Science Foundation of Hebei Province","doi-asserted-by":"publisher","award":["E2026203211"],"award-info":[{"award-number":["E2026203211"]}],"id":[{"id":"10.13039\/501100003787","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2022YFA1402300"],"award-info":[{"award-number":["2022YFA1402300"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFA1406200"],"award-info":[{"award-number":["2023YFA1406200"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["2025M781016"],"award-info":[{"award-number":["2025M781016"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China (NSFC)","doi-asserted-by":"crossref","award":["52090020"],"award-info":[{"award-number":["52090020"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China (NSFC)","doi-asserted-by":"crossref","award":["52288102"],"award-info":[{"award-number":["52288102"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China (NSFC)","doi-asserted-by":"crossref","award":["52372157"],"award-info":[{"award-number":["52372157"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,19]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Graphite intercalation compounds (GICs) serve as a highly tunable platform for exploring phonon-mediated superconductivity in lightweight materials. While theoretical models have long predicted that densely packed, first-stage (stage-1) sodium-intercalated graphite (Na-GIC) could host elevated critical temperatures (Tc), its experimental synthesis has remained a formidable challenge. Here, we report the realization of stage-1 Na-GIC that exhibits bulk superconductivity and achieves a maximum onset Tc of \u223c31 K, setting a record for all known GIC systems. By employing a room-temperature mechanical synthesis with an excess sodium reservoir, followed by lattice compression, we force a sequential staging transition in Na-GIC\u2500from an initial stage-8, through an intermediate stage-2, and ultimately to the densely intercalated stage-1 phase at 15.6 GPa. By correlating room-temperature in situ synchrotron X-ray diffraction with evolutionary structural searches, we identify the host of this high-Tc state as an orthorhombic NaC3 structure with Imma symmetry. First-principles calculations reveal a remarkably strong electron\u2013phonon coupling (\u03bb \u223c 2.0), dominated by interactions between out-of-plane carbon \u03c0 electrons and low-frequency Na\/C vibrations. Our findings not only capture the elusive stage-1 Na-GIC but also establish pressure-driven compositional tuning as a robust strategy to unlock high-Tc states in carbon-based superlattices.<\/jats:p>","DOI":"10.1021\/jacs.6c10866","type":"journal-article","created":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T14:38:49Z","timestamp":1785854329000},"page":"34888-34894","source":"Crossref","is-referenced-by-count":1,"title":["Superconductivity\nat 31 K in a Stage-1 Sodium-Intercalated\nGraphite"],"prefix":"10.1021","volume":"148","author":[{"given":"Yuan-Qing","family":"Liu","sequence":"first","affiliation":[{"name":"Nankai University , , ,","place":["Tianjin, China, 300071"]},{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ming-Xing","family":"Huang","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]},{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chun-Mei","family":"Hao","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]},{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5779-3176","authenticated-orcid":true,"given":"Jingyu","family":"Hou","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3083-472X","authenticated-orcid":true,"given":"Guochun","family":"Yang","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiajia","family":"Feng","sequence":"additional","affiliation":[{"name":"Center for High Pressure Science and Technology Advanced Research , ,","place":["Beijing, China, 100193"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bin","family":"Chen","sequence":"additional","affiliation":[{"name":"Center for High Pressure Science and Technology Advanced Research , ,","place":["Beijing, China, 100193"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Ding","sequence":"additional","affiliation":[{"name":"Center for High Pressure Science and Technology Advanced Research , ,","place":["Beijing, China, 100193"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaobo","family":"Yu","sequence":"additional","affiliation":[{"name":"Nanjing University , , ,","place":["Nanjing, China, 210093"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6172-9100","authenticated-orcid":true,"given":"Jian","family":"Sun","sequence":"additional","affiliation":[{"name":"Nanjing University , , ,","place":["Nanjing, China, 210093"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lin","family":"Wang","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9804-1614","authenticated-orcid":true,"given":"Bo","family":"Xu","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1906-9636","authenticated-orcid":true,"given":"Feng","family":"Ke","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8651-9273","authenticated-orcid":true,"given":"Xiang-Feng","family":"Zhou","sequence":"additional","affiliation":[{"name":"Nankai University , , ,","place":["Tianjin, China, 300071"]},{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]},{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4594-4879","authenticated-orcid":true,"given":"Yongjun","family":"Tian","sequence":"additional","affiliation":[{"name":"Yanshan University , , ,","place":["Qinhuangdao, China, 066004"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,1]]},"reference":[{"key":"2026081910233804800_cit1","doi-asserted-by":"publisher","first-page":"1175","DOI":"10.1103\/PhysRev.108.1175","article-title":"Theory of Superconductivity","volume":"108","author":"Bardeen","year":"1957","journal-title":"Phys. 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Phys."},{"key":"2026081910233804800_cit16","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1016\/j.physc.2015.02.029","article-title":"Superconductivity in Graphite Intercalation\nCompounds","volume":"514","author":"Smith","year":"2015","journal-title":"Physica C"},{"key":"2026081910233804800_cit17","doi-asserted-by":"publisher","first-page":"3493","DOI":"10.1038\/ncomms4493","article-title":"Superconducting Graphene Sheets in CaC6 Enabled\nby Phonon-Mediated Interband Interactions","volume":"5","author":"Yang","year":"2014","journal-title":"Nat.\nCommun."},{"key":"2026081910233804800_cit18","doi-asserted-by":"publisher","first-page":"247201","DOI":"10.1103\/PhysRevLett.114.247201","article-title":"Superconductivity\nin the Graphite Intercalation Compound BaC6","volume":"114","author":"Heguri","year":"2015","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit19","doi-asserted-by":"publisher","first-page":"225","DOI":"10.1103\/PhysRevLett.14.225","article-title":"Superconductivity in\nGraphitic Compounds","volume":"14","author":"Hannay","year":"1965","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit20","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1038\/nphys0010","article-title":"Superconductivity\nin the Intercalated Graphite Compounds C6Yb and C6Ca","volume":"1","author":"Weller","year":"2005","journal-title":"Nat. Phys."},{"key":"2026081910233804800_cit21","doi-asserted-by":"publisher","first-page":"087003","DOI":"10.1103\/PhysRevLett.95.087003","article-title":"Superconductivity\nof Bulk CaC6","volume":"95","author":"Emery","year":"2005","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit22","doi-asserted-by":"publisher","first-page":"132502","DOI":"10.1103\/PhysRevB.82.132502","article-title":"Superconductivity for\nCaC6 to 32 GPa Hydrostatic Pressure","volume":"82","author":"Debessai","year":"2010","journal-title":"Phys. Rev.\nB"},{"key":"2026081910233804800_cit23","doi-asserted-by":"publisher","first-page":"067002","DOI":"10.1103\/physrevlett.98.067002","article-title":"Enhancement\nof Superconductivity and Evidence of Structural Instability in Intercalated\nGraphite CaC6 under High Pressure","volume":"98","author":"Gauzzi","year":"2007","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit24","doi-asserted-by":"publisher","first-page":"arXiv:2509.23137","DOI":"10.48550\/arXiv.2509.23137","article-title":"Superconductivity at\n22.3 K in Compressed Sodium-Intercalated Graphite","author":"Huang","year":"2025","journal-title":"arXiv"},{"key":"2026081910233804800_cit25","doi-asserted-by":"publisher","first-page":"166003","DOI":"10.1103\/2t6l-sqmj","article-title":"Superconductivity\nat 28 K in Sodium Graphite Intercalation Compound under High Pressure","volume":"135","author":"Ma","year":"2025","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit26","doi-asserted-by":"publisher","first-page":"214507","DOI":"10.1103\/PhysRevB.108.214507","article-title":"Superconductivity\nin Compounds of\nSodium-Intercalated Graphite","volume":"108","author":"Hao","year":"2023","journal-title":"Phys. Rev. B"},{"key":"2026081910233804800_cit27","doi-asserted-by":"publisher","first-page":"174508","DOI":"10.1103\/PhysRevB.110.174508","article-title":"Stability-Superconductivity Map for Compressed Na-Intercalated\nGraphite","volume":"110","author":"Mishra","year":"2024","journal-title":"Phys. Rev. B"},{"key":"2026081910233804800_cit28","doi-asserted-by":"publisher","first-page":"363","DOI":"10.1016\/0379-6779(80)90071-5","article-title":"New Results about the\nSodium-Graphite System","volume":"1","author":"Metrot","year":"1980","journal-title":"Synth. Met."},{"key":"2026081910233804800_cit29","doi-asserted-by":"publisher","first-page":"214505","DOI":"10.1103\/PhysRevB.98.214505","article-title":"Superconducting\nProperties of the Noncentrosymmetric Superconductor LaPtGe","volume":"98","author":"S","year":"2018","journal-title":"Phys. Rev. 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Technol."},{"key":"2026081910233804800_cit31","doi-asserted-by":"publisher","first-page":"531","DOI":"10.1038\/s41586-024-07553-3","article-title":"Superconductivity in\nPressurized Trilayer La4Ni3O10\u2212\u03b4 Single Crystals","volume":"631","author":"Zhu","year":"2024","journal-title":"Nature"},{"key":"2026081910233804800_cit32","doi-asserted-by":"publisher","first-page":"624","DOI":"10.1038\/s41586-019-1496-5","article-title":"Superconductivity\nin an Infinite-Layer\nNickelate","volume":"572","author":"Li","year":"2019","journal-title":"Nature"},{"key":"2026081910233804800_cit33","doi-asserted-by":"publisher","first-page":"630","DOI":"10.1038\/nmat2491","article-title":"Electronic and Magnetic\nPhase Diagram\nof \u03b2-Fe1.01Se with Superconductivity at 36.7 K under\nPressure","volume":"8","author":"Medvedev","year":"2009","journal-title":"Nat. Mater."},{"key":"2026081910233804800_cit34","doi-asserted-by":"publisher","first-page":"012126","DOI":"10.1088\/1742-6596\/200\/1\/012126","article-title":"Magnetic Measurements\nof FeSe Superconductor under High Pressure","volume":"200","author":"Miyoshi","year":"2010","journal-title":"J. Phys. Conf. Ser."},{"key":"2026081910233804800_cit35","doi-asserted-by":"publisher","first-page":"094917","DOI":"10.1063\/1.1895467","article-title":"Optical calibration\nof pressure sensors for high pressures and temperatures","volume":"97","author":"Goncharov","year":"2005","journal-title":"J. Appl. Phys."},{"key":"2026081910233804800_cit36","doi-asserted-by":"publisher","first-page":"025501","DOI":"10.1088\/0957-0233\/26\/2\/025501","article-title":"Pressure estimation\nusing the diamond Raman scale at\nlow pressures in diamond anvil cell experiments using a highly confocal\nRaman system","volume":"26","author":"Fujii","year":"2015","journal-title":"Meas. Sci. Technol."},{"key":"2026081910233804800_cit37","doi-asserted-by":"publisher","first-page":"905","DOI":"10.1103\/PhysRevB.12.905","article-title":"Transition Temperature of Strong-Coupled\nSuperconductors\nReanalyzed","volume":"12","author":"Allen","year":"1975","journal-title":"Phys. Rev. B:"},{"key":"2026081910233804800_cit38","doi-asserted-by":"publisher","first-page":"1460","DOI":"10.1103\/PhysRevLett.59.1460","article-title":"Theory\nof Thermal Relaxation of Electrons in Metals","volume":"59","author":"Allen","year":"1987","journal-title":"Phys. Rev. Lett."},{"key":"2026081910233804800_cit39","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2536178123","article-title":"Ambient-Pressure\n151-K Superconductivity in HgBa2Ca2Cu3O8+\u03b4 via Pressure Quench","volume":"123","author":"Deng","year":"2026","journal-title":"Proc. Natl. Acad. Sci. U. S. A."}],"container-title":["Journal of the American\nChemical Society"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/jacs.6c10866","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/jacsat\/article-pdf\/148\/32\/34888\/66354482\/jacs.6c10866.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/jacsat\/article-pdf\/148\/32\/34888\/66354482\/jacs.6c10866.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T14:32:50Z","timestamp":1787149970000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/jacsat\/article\/148\/32\/34888\/5238319\/Superconductivity-at-31-K-in-a-Stage-1-Sodium"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,1]]},"references-count":39,"journal-issue":{"issue":"32","published-online":{"date-parts":[[2026,8,1]]},"published-print":{"date-parts":[[2026,8,19]]}},"URL":"https:\/\/doi.org\/10.1021\/jacs.6c10866","relation":{},"ISSN":["0002-7863","1520-5126"],"issn-type":[{"value":"0002-7863","type":"print"},{"value":"1520-5126","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,1]]}}}