Source zotero
Authors Zehao Dong, Gang Wang, Ningning Wang, Wen-Han Dong, Lin Gu, Yong Xu, Jinguang Cheng, Zhen Chen, Yayu Wang
arXiv / Publisher https://www.nature.com/articles/s41563-025-02351-2
PDF https://www.nature.com/articles/s41563-025-02351-2.pdf
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Primary category Not available in this batch.
Published 2025-09-15
Research paradigm Experimental
Sample form Unknown

Summary

High-temperature superconductivity in pressurized La3Ni2O7 has attracted considerable interest, yet the superconducting phase is rather fragile. Although bulk superconductivity can be achieved by Pr substitution for La, the underlying mechanism is still unclear. A further puzzle is the role of oxygen content: moderate oxygenation enhances superconductivity, whereas high-pressure oxygen annealing suppresses it. Here combining multislice electron ptychography and electron energy-loss spectroscopy, we show that Pr doping mitigates oxygen vacancies and stabilizes a near-stoichiometric La2PrNi2O7 structure. Strikingly, high-pressure oxygen annealing introduces interstitial oxygen atoms that arrange into a stripe-ordered superstructure, which generates excess hole carriers and alters the electronic structure, ultimately suppressing superconductivity under pressure. This contrasts sharply with cuprates, where similar oxygen ordering is known to induce superconductivity. Our findings reveal a competition between interstitial oxygen ordering and superconductivity in bilayer nickelates, providing key insights into the pairing mechanism and guiding principles for engineering more robust superconducting phases.

Materials

Methods

  • multislice electron ptychography
  • electron energy-loss spectroscopy

Keywords

Highlights

  • Direct visualization of interstitial oxygen order using multislice electron ptychography.
  • Discovery of stripe-ordered superstructure of interstitial oxygen that suppresses superconductivity.
  • Contrast with cuprates provides key insights into pairing mechanism.

Conclusions

  • Pr doping mitigates oxygen vacancies and stabilizes near-stoichiometric La2PrNi2O7 structure.
  • High-pressure oxygen annealing introduces interstitial oxygen atoms that arrange into a stripe-ordered superstructure, generating excess hole carriers and altering electronic structure, suppressing superconductivity under pressure.
  • This contrasts with cuprates where similar oxygen ordering induces superconductivity.
  • Reveals competition between interstitial oxygen ordering and superconductivity in bilayer nickelates.

Main claims

Not available in this batch.

Workflow

Not available in this batch.