Presentation Information
[PC7-03]Identification of Superconductivity in Bilayer Nickelate La3Ni2O7 under High Pressure up to 100 GPa
*Jingyuan Li1, Di Peng2, Peiyue Ma1, Hualei Sun3, Qiaoshi Zeng2,4, Ho-kwang Mao2,4, Meng Wang1 (1. School of Physics, Sun Yat-Sen University (China), 2. Institute for Shanghai Advanced Research in Physical Sciences (China), 3. School of Science, Sun Yat-Sen University (China), 4. Center for High Pressure Science & Technology Advanced Research (China))
Keywords:
Nickelates,High-temperature superconductivity,High-pressure technique,Meissner effect
[Purpose]
The recent discovery of 80 K superconductivity in bilayer nickelate La3Ni2O7 reignited enthusiasm of high-temperature superconductivity. However, the further evolution of superconductivity under pressure remains unclear. The filamentary or bulk nature of superconductivity, the crystal structure under pressure are under debate. In this work, we aimed to address these issues of bilayer nickelate La3Ni2O7 under hydrostatic pressures up to 104 GPa.
[Method]
In this work, we conducted high-pressure electronic transport measurement, in situ high-pressure synchrotron X-ray diffraction measurement and high-pressure direct-current magnetic susceptibility measurement on La3Ni2O7.
[Results]
High-pressure transport measurement shows the superconductivity emerges around 10 GPa. A maximum onset transition temperature Tconset of 83 K at 18.0 GPa is achieved and accompanied by zero resistance. The superconducting phase is gradually suppressed and vanishes above 80 GPa. High-pressure synchrotron X-ray diffraction shows a structural transition from an orthorhombic to a tetragonal phase above 40 GPa. By adopting high-pressure direct-current magnetic susceptibility measurement, we observed the Meissner effect and derived a superconducting volume fraction of ~41% at 20 K under 22.0 GPa.
[Consideration]
Firstly, our experiments depicts the whole superconducting phase diagram of La3Ni2O7 and its intricate relation with structural transition. Secondly, the 41% superconducting volume fraction verifies the bulk superconductivity of La3Ni2O7 for the first time.
[Conclusion]
Based on our results, a right-triangle-like superconducting phase diagram of La3Ni2O7 was obtained. The crystal structure where the superconductivity emerges is still in the orthorhombic phase. Furthermore, the bulk nature of superconductivity in La3Ni2O7 was for the first time confirmed. Our results provides solid experimental foundation of further understanding of the underlying pairing mechanism of bilayer nickelate La3Ni2O7.
The recent discovery of 80 K superconductivity in bilayer nickelate La3Ni2O7 reignited enthusiasm of high-temperature superconductivity. However, the further evolution of superconductivity under pressure remains unclear. The filamentary or bulk nature of superconductivity, the crystal structure under pressure are under debate. In this work, we aimed to address these issues of bilayer nickelate La3Ni2O7 under hydrostatic pressures up to 104 GPa.
[Method]
In this work, we conducted high-pressure electronic transport measurement, in situ high-pressure synchrotron X-ray diffraction measurement and high-pressure direct-current magnetic susceptibility measurement on La3Ni2O7.
[Results]
High-pressure transport measurement shows the superconductivity emerges around 10 GPa. A maximum onset transition temperature Tconset of 83 K at 18.0 GPa is achieved and accompanied by zero resistance. The superconducting phase is gradually suppressed and vanishes above 80 GPa. High-pressure synchrotron X-ray diffraction shows a structural transition from an orthorhombic to a tetragonal phase above 40 GPa. By adopting high-pressure direct-current magnetic susceptibility measurement, we observed the Meissner effect and derived a superconducting volume fraction of ~41% at 20 K under 22.0 GPa.
[Consideration]
Firstly, our experiments depicts the whole superconducting phase diagram of La3Ni2O7 and its intricate relation with structural transition. Secondly, the 41% superconducting volume fraction verifies the bulk superconductivity of La3Ni2O7 for the first time.
[Conclusion]
Based on our results, a right-triangle-like superconducting phase diagram of La3Ni2O7 was obtained. The crystal structure where the superconductivity emerges is still in the orthorhombic phase. Furthermore, the bulk nature of superconductivity in La3Ni2O7 was for the first time confirmed. Our results provides solid experimental foundation of further understanding of the underlying pairing mechanism of bilayer nickelate La3Ni2O7.