Source zotero
Authors Lifen Xiang, Siyi Lei, Xiaolin Ren, Ziao Han, Zijian Xu, X. J. Zhou, Zhihai Zhu
arXiv / Publisher https://link.aps.org/doi/10.1103/h9ls-y4s7
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Published 2026-03-25
Research paradigm Unknown
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Summary

Stabilizing and tuning superconductivity in La3Ni2O7−δ films: Oxygen recycling protocol reveals hole-doping analogue

Materials

Not available in this batch.

Methods

Not available in this batch.

Keywords

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Highlights

Not available in this batch.

Conclusions

Not available in this batch.

Main claims

  • A two-step recycling protocol (oxygen removal in air followed by ozone annealing) effectively restores superconductivity in degraded La3Ni2O7-δ films.
    • Evidence: Transport and XRD show recovery of superconducting transition and structural peaks after the two-step process.
  • Oxygen addition in La3Ni2O7-δ films acts as an analog to hole doping via Sr substitution, revealed by an electronic phase diagram with asymmetric superconducting region.
    • Evidence: XAS shows changes in Ni dz2 bonding band; transport phase diagram shows similar behavior to Sr-doped films.

Workflow

  • Film Growth — Compressive strain and oxygen stoichiometry are key factors.
    • Materials: La3Ni2O7-δ; SrLaAlO4 (SLAO) substrate
    • Methods: pulsed laser deposition (PLD)
    • Observations: films grown on SLAO show compressive strain
  • Ozone Annealing — Ozone annealing tunes oxygen content and induces superconductivity.
    • Materials: La3Ni2O7-δ films
    • Methods: ozone annealing post-growth
    • Observations: films evolve from insulator to metal to superconductor
  • Transport Measurements — Superconductivity is achieved in thin films on SLAO with Tc ≈40 K.
    • Materials: La3Ni2O7-δ films
    • Methods: four-probe resistivity; magnetic field up to 9T
    • Observations: superconducting transition at ≈42 K; upper critical field ≈27-58T
  • X-ray Diffraction (XRD) — Two-step process restores crystalline structure.
    • Materials: La3Ni2O7-δ films
    • Methods: out-of-plane XRD
    • Observations: diffraction peaks weaken upon degradation and recover after two-step process
  • X-ray Absorption Spectroscopy (XAS) — Oxygen addition mimics hole doping by La substitution with Sr.
    • Materials: La3Ni2O7-δ films on SLAO
    • Methods: XAS at O-K and Ni-L3 edges; linear dichroism (XLD)
    • Observations: holes in Ni dz2 bonding band in as-grown films; suppressed in superconducting films