Bulk high-temperature superconductivity in pressurized tetragonal La2PrNi2O7

• 成果类型: Article
• 署名作者: Wang, Ningning; Wang, Gang; Shen, Xiaoling; Hou, Jun; Luo, Jun; Ma, Xiaoping; Yang, Huaixin; Shi, Lifen; Dou, Jie; Feng, Jie; Yang, Jie; Shi, Yunqing; Ren, Zhian; Ma, Hanming; Yang, Pengtao; Liu, Ziyi; Liu, Yue; Zhang, Hua; Dong, Xiaoli; Wang, Yuxin; Jiang, Kun; Hu, Jiangping; Nagasaki, Shoko; Kitagawa, Kentaro; Calder, Stuart; Yan, Jiaqiang; Sun, Jianping; Wang, Bosen; Zhou, Rui; Uwatoko, Yoshiya; Cheng, Jinguang
• 署名单位: Chinese Academy of Sciences; Chinese Academy of Sciences; Institute of Physics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; University of Tokyo; Shanghai Jiao Tong University; United States Department of Energy (DOE); Oak Ridge National Laboratory; United States Department of Energy (DOE); Oak Ridge National Laboratory
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6235
• DOI: 10.1038/s41586-024-07996-8
• 发表日期: 2024-10-17
• 页码: 579-+
• 关键词: phase; ORDER

摘要

The Ruddlesden-Popper (R-P) bilayer nickelate, La3Ni2O7, was recently found to show signatures of high-temperature superconductivity (HTSC) at pressures above 14 GPa (ref. 1). Subsequent investigations achieved zero resistance in single-crystalline and polycrystalline samples under hydrostatic pressure conditions(2-4). Yet, obvious diamagnetic signals, the other hallmark of superconductors, are still lacking owing to the filamentary nature with low superconducting volume fraction(2,4,5). The presence of a new 1313 polymorph and competing R-P phases obscured proper identification of the phase for HTSC6-9. Thus, achieving bulk HTSC and identifying the phase at play are the most prominent tasks. Here we address these issues in the praseodymium (Pr)-doped La2PrNi2O7 polycrystalline samples. We find that substitutions of Pr for La effectively inhibit the intergrowth of different R-P phases, resulting in a nearly pure bilayer structure. For La2PrNi2O7, pressure-induced orthorhombic to tetragonal structural transition takes place at P-c approximate to 11 GPa, above which HTSC emerges gradually on further compression. The superconducting transition temperatures at 18-20 GPa reach T-c(onset) = 82.5 K and T-c(zero) = 60 K , which are the highest values, to our knowledge, among known nickelate superconductors. Importantly, bulk HTSC was testified by detecting clear diamagnetic signals below about 75 K with appreciable superconducting shielding volume fractions at a pressure of above 15 GPa. Our results not only resolve the existing controversies but also provide directions for exploring bulk HTSC in the bilayer nickelates.