{"title":"Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films","authors":"Guangdi Zhou, Wei Lv, Heng Wang, Zihao Nie, Yaqi Chen, Yueying Li, Haoliang Huang, Wei-Qiang Chen, Yu-Jie Sun, Qi-Kun Xue, Zhuoyu Chen","doi":"10.1038/s41586-025-08755-z","DOIUrl":null,"url":null,"abstract":"The discovery of Ruddlesden–Popper (RP) bilayer nickelate superconductors under high pressure has opened a new chapter in high-transition-temperature superconductivity1–8. However, the high-pressure conditions and presence of impurity phases have hindered comprehensive investigations into their superconducting properties and potential applications. Here we report ambient-pressure superconductivity onset above the McMillan limit (40 K) in RP bilayer nickelate epitaxial thin films. Three-unit-cell-thick La2.85Pr0.15Ni2O7 pure-phase single-crystal films are grown using the gigantic-oxidative atomic layer-by-layer epitaxy on SrLaAlO4 substrates9. Resistivity measurements and magnetic field responses indicate onset transition temperature of 45 K. The transition to zero resistance shows characteristics consistent with a Berezinskii–Kosterlitz–Thouless (BKT) behaviour, with TBKT = 9 K. The Meissner diamagnetic effect is observed at 8 K by using a mutual inductance setup, in agreement with the BKT-like transition. In- and out-of-plane critical magnetic fields show anisotropy. Scanning transmission electron microscopy images and X-ray reciprocal space mappings reveal that the RP bilayer nickelate films adopt a tetragonal phase under roughly 2% coherent epitaxial compressive strain in the NiO2 planes relative to the bulk. Our findings pave the way for comprehensive investigations of nickelate superconductors under ambient pressure conditions and for exploring superconductivity at higher transition temperatures through strain engineering in heterostructures. Ambient-pressure superconductivity onset above the McMillan limit in bilayer nickelate epitaxial thin films is reported, paving the way for comprehensive investigations of superconductors and for exploring superconductivity at higher transition temperatures in heterostructures.","PeriodicalId":18787,"journal":{"name":"Nature","volume":"640 8059","pages":"641-646"},"PeriodicalIF":50.5000,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature","FirstCategoryId":"103","ListUrlMain":"https://www.nature.com/articles/s41586-025-08755-z","RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The discovery of Ruddlesden–Popper (RP) bilayer nickelate superconductors under high pressure has opened a new chapter in high-transition-temperature superconductivity1–8. However, the high-pressure conditions and presence of impurity phases have hindered comprehensive investigations into their superconducting properties and potential applications. Here we report ambient-pressure superconductivity onset above the McMillan limit (40 K) in RP bilayer nickelate epitaxial thin films. Three-unit-cell-thick La2.85Pr0.15Ni2O7 pure-phase single-crystal films are grown using the gigantic-oxidative atomic layer-by-layer epitaxy on SrLaAlO4 substrates9. Resistivity measurements and magnetic field responses indicate onset transition temperature of 45 K. The transition to zero resistance shows characteristics consistent with a Berezinskii–Kosterlitz–Thouless (BKT) behaviour, with TBKT = 9 K. The Meissner diamagnetic effect is observed at 8 K by using a mutual inductance setup, in agreement with the BKT-like transition. In- and out-of-plane critical magnetic fields show anisotropy. Scanning transmission electron microscopy images and X-ray reciprocal space mappings reveal that the RP bilayer nickelate films adopt a tetragonal phase under roughly 2% coherent epitaxial compressive strain in the NiO2 planes relative to the bulk. Our findings pave the way for comprehensive investigations of nickelate superconductors under ambient pressure conditions and for exploring superconductivity at higher transition temperatures through strain engineering in heterostructures. Ambient-pressure superconductivity onset above the McMillan limit in bilayer nickelate epitaxial thin films is reported, paving the way for comprehensive investigations of superconductors and for exploring superconductivity at higher transition temperatures in heterostructures.
期刊介绍:
Nature is a prestigious international journal that publishes peer-reviewed research in various scientific and technological fields. The selection of articles is based on criteria such as originality, importance, interdisciplinary relevance, timeliness, accessibility, elegance, and surprising conclusions. In addition to showcasing significant scientific advances, Nature delivers rapid, authoritative, insightful news, and interpretation of current and upcoming trends impacting science, scientists, and the broader public. The journal serves a dual purpose: firstly, to promptly share noteworthy scientific advances and foster discussions among scientists, and secondly, to ensure the swift dissemination of scientific results globally, emphasizing their significance for knowledge, culture, and daily life.