Abstract
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 susceptibility measurements up to 15 GPa, indicating a filamentary nature of the observed superconductivity in the studied pressure range. The constructed T-P phase diagram reveals an intimate relationship between superconductivity, density-wave-like order, and the strange-metal-like behaviors. The observation of zero-resistance state in the polycrystalline La3Ni2O7-δ samples under high pressures not only corroborates the recent report of superconductivity in the pressurized La3Ni2O7 crystals but also facilitates further studies on this emerging family of nickelate high-Tc superconductors.
| Original language | English |
|---|---|
| Article number | 011040 |
| Journal | Physical Review X |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2024 |
Funding
We are grateful to Professor Zhongxian Zhao for the insightful discussions and we also thank Professor Meng Wang for the previous collaboration on the LaNiO crystals. This work is supported by the National Natural Science Foundation of China (Grants No. 12025408, No. 11921004, No. 12174424, and No. 11888101), National Key Research and Development Program of China (Grant No. 2021YFA1400200), the Strategic Priority Research Program of CAS (Grant No. XDB33000000), the China Postdoctoral Science Foundation (Grant No. 2023M743740), the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation (Grant No. GZB20230828), the Specific Research Assistant Funding Program of CAS (Grant No. E3VP011X61), the CAS Project for Young Scientists in Basic Research (Grants No. 2022YSBR-047 and No. 2022YSBR-048), the Youth Innovation Promotion Association of CAS (Grant No. 2023007), and the President’s International Fellowship Initiative (Grant No. 2024PG0003). J.-Q. Y was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The high-pressure experiments were performed at the Cubic Anvil Cell station of Synergic Extreme Condition User Facility (SECUF). This research used resources at the High Flux Isotope Reactor, a U.S. DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. 3 2 7