Pressure-Induced Superconductivity In Polycrystalline La 3 Ni 2 O 7 − δ

We synthesized polycrystalline La3Ni2O7−δ (δ≈0.07) samples by using the sol-gel method without postannealing under high oxygen pressure, and then measured temperature-dependent resistivity under various hydrostatic pressures up to 18 GPa by using the cubic anvil and two-stage multianvil apparatus. We find that the density-wave-like anomaly in resistivity is progressively suppressed with increasing pressure and the resistivity drop corresponding to the onset of superconductivity emerges at pressure as low as ∼6 GPa. Zero resistivity is achieved at 9 GPa below Tczero≈6.6 K, which increases quickly with pressure to 41 K at 18 GPa. However, the diamagnetic response was not detected in the ac magnetic…

• UD
  U.S. Department of Energy
• NN
  National Natural Science Foundation of China

  Awards: XDB33000000, 12025408, 11921004, 12174424, 11888101
• CP
  China Postdoctoral Science Foundation

  Awards: 2023M743740, GZB20230828
• YI
  Youth Innovation Promotion Association of the Chinese Academy of Sciences

  Award: 2023007
• OO
  Office of Science
• NK
  National Key Research and Development Program of China

  Awards: XDB33000000, 11888101, 2021YFA1400200
• YI
  Youth Innovation Promotion Association

  Awards: 2023007, 2022YSBR-048
• BE
  Basic Energy Sciences
• OR
  Oak Ridge National Laboratory
• DO
  Division of Materials Sciences and Engineering