Abstract
The discovery of superconductivity under high pressure in Ruddlesden–Popper phases of bulk nickelates has sparked great interest in stabilizing ambient-pressure superconductivity in the thin-film form using epitaxial strain. Recently, signs of superconductivity have been observed in compressively strained bilayer nickelate thin films with an onset temperature exceeding 40 K, although with broad, two-step-like transitions. Here we report the intrinsic superconductivity and normal-state transport properties in compressively strained La2PrNi2O7 thin films, achieved through a combination of isovalent Pr substitution, growth optimization and precision ozone annealing. The superconducting onset occurs above 48 K, with zero resistance reached above 30 K, and the critical current density at 1.4 K is 100-fold larger than previous reports. The normal-state resistivity exhibits quadratic temperature dependence indicative of Fermi liquid behaviour, and other phenomenological similarities to transport in overdoped cuprates suggest parallels in their emergent properties.
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Any additional data that support the findings of this study are available from the corresponding authors upon reasonable request. Source data are provided with this paper.
References
Sun, H. et al. Signatures of superconductivity near 80 K in a nickelate under high pressure. Nature 621, 493–498 (2023).
Zhang, Y. et al. High-temperature superconductivity with zero resistance and strange-metal behaviour in La3Ni2O7–δ. Nat. Phys. 20, 1269–1273 (2024).
Wang, G. et al. Pressure-induced superconductivity in polycrystalline La3Ni2O7–δ. Phys. Rev. X 14, 011040 (2024).
Zhu, Y. et al. Superconductivity in pressurized trilayer La4Ni3O10−δ single crystals. Nature 631, 531–536 (2024).
Wang, N. et al. Bulk high-temperature superconductivity in pressurized tetragonal La2PrNi2O7. Nature 634, 579–584 (2024).
Wang, M., Wen, H.-H., Wu, T., Yao, D.-X. & Xiang, T. Normal and superconducting properties of La3Ni2O7. Chinese Phys. Lett. 41, 077402 (2024).
Locquet, J.-P. et al. Doubling the critical temperature of La1.9Sr0.1CuO4 using epitaxial strain. Nature 394, 453–456 (1998).
Bozovic, I., Logvenov, G., Belca, I., Narimbetov, B. & Sveklo, I. Epitaxial strain and superconductivity in La2–xSrxCuO4 thin films. Phys. Rev. Lett. 89, 107001 (2002).
Ko, E. K. et al. Signatures of ambient pressure superconductivity in thin film La3Ni2O7. Nature 638, 935–940 (2025).
Zhou, G. et al. Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films. Nature 640, 641–646 (2025).
Puphal, P. et al. Unconventional crystal structure of the high-pressure superconductor La3Ni2O7. Phys. Rev. Lett. 133, 146002 (2024).
Chen, X. et al. Polymorphism in the Ruddlesden–Popper nickelate La3Ni2O7: discovery of a hidden phase with distinctive layer stacking. J. Am. Chem. Soc. 146, 3640–3645 (2024).
Wang, H., Chen, L., Rutherford, A., Zhou, H. & Xie, W. Long-range structural order in a hidden phase of Ruddlesden–Popper bilayer nickelate La3Ni2O7. Inorg. Chem. 63, 5020–5026 (2024).
Zinkevich, M., Solak, N., Nitsche, H., Ahrens, M. & Aldinger, F. Stability and thermodynamic functions of lanthanum nickelates. J. Alloys Compd. 438, 92–99 (2007).
Cui, T. et al. Strain-mediated phase crossover in Ruddlesden–Popper nickelates. Commun. Mater. 5, 32 (2024).
Li, D. et al. Superconductivity in an infinite-layer nickelate. Nature 572, 624–627 (2019).
Smith, J. A., Cima, M. J. & Sonnenberg, N. High critical current density thick MOD-derived YBCO films. IEEE Trans. Appl. Supercond. 9, 1531–1534 (1999).
Wang, L. et al. Structure responsible for the superconducting state in La3Ni2O7 at high-pressure and low-temperature conditions. J. Am. Chem. Soc. 146, 7506–7514 (2024).
Li, J. et al. Identification of the superconductivity in bilayer nickelate La3Ni2O7 upon 100 GPa. Preprint at https://arxiv.org/abs/2404.11369 (2025).
Dong, Z. et al. Visualization of oxygen vacancies and self-doped ligand holes in La3Ni2O7–δ. Nature 630, 847–852 (2024).
Batakliev, T., Georgiev, V., Anachkov, M., Rakovsky, S. & Rakovsky, S. Ozone decomposition. Interdiscip. Toxicol. 7, 47–59 (2014).
Wiesmann, H. et al. Simple model for characterizing the electrical resistivity in A – 15 superconductors. Phys. Rev. Lett. 38, 782–785 (1977).
Cooper, R. A. et al. Anomalous criticality in the electrical resistivity of La2–xSrxCuO4. Science 323, 603–607 (2009).
Hussey, N. E. Phenomenology of the normal state in-plane transport properties of high-Tc cuprates. J. Phys. Condens. Matter 20, 123201 (2008).
Hwang, H. Y. et al. Scaling of the temperature dependent Hall effect in La2–xSrxCuO4. Phys. Rev. Lett. 72, 2636–2639 (1994).
Zhou, Y. et al. Investigations of key issues on the reproducibility of high-Tc superconductivity emerging from compressed La3Ni2O7. Matter Radiat. Extrem. 10, 027801 (2025).
Gu, Y., Le, C., Yang, Z., Wu, X. & Hu, J. Effective model and pairing tendency in the bilayer Ni-based superconductor La3Ni2O7. Phys. Rev. B 111, 174506 (2025).
Zhang, Y., Lin, L.-F., Moreo, A. & Dagotto, E. Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La3Ni2O7 under pressure. Phys. Rev. B 108, L180510 (2023).
Christiansson, V., Petocchi, F. & Werner, P. Correlated electronic structure of La3Ni2O7 under pressure. Phys. Rev. Lett. 131, 206501 (2023).
Lechermann, F., Gondolf, J., Bötzel, S. & Eremin, I. M. Electronic correlations and superconducting instability in La3Ni2O7 under high pressure. Phys. Rev. B 108, L201121 (2023).
Yang, Q.-G., Wang, D. & Wang, Q.-H. Possible s±-wave superconductivity in La3Ni2O7. Phys. Rev. B 108, L140505 (2023).
Liu, Y.-B., Mei, J.-W., Ye, F., Chen, W.-Q. & Yang, F. s±-wave pairing and the destructive role of apical-oxygen deficiencies in La3Ni2O7 under pressure. Phys. Rev. Lett. 131, 236002 (2023).
Yang, Y., Zhang, G.-M. & Zhang, F.-C. Interlayer valence bonds and two-component theory for high-Tc superconductivity of La3Ni2O7 under pressure. Phys. Rev. B 108, L201108 (2023).
Shen, Y., Qin, M. & Zhang, G.-M. Effective bi-layer model Hamiltonian and density-matrix renormalization group study for the high-Tc superconductivity in La3Ni2O7 under high pressure. Chinese Phys. Lett. 40, 127401 (2023).
Qin, Q. & Yang, Y. High-Tc superconductivity by mobilizing local spin singlets and possible route to higher Tc in pressurized La3Ni2O7. Phys. Rev. B 108, L140504 (2023).
Luo, Z., Lv, B., Wang, M., Wú, W. & Yao, D.-X. High-Tc superconductivity in La3Ni2O7 based on the bilayer two-orbital t-J model. npj Quantum Mater. 9, 61 (2024).
Sakakibara, H., Kitamine, N., Ochi, M. & Kuroki, K. Possible high Tc superconductivity in La3Ni2O7 under high pressure through manifestation of a nearly half-filled bilayer Hubbard model. Phys. Rev. Lett. 132, 106002 (2024).
Geisler, B., Hamlin, J. J., Stewart, G. R., Hennig, R. G. & Hirschfeld, P. J. Fermi surface reconstruction in strained La3Ni2O7 on LaAlO3(001) and SrTiO3(001). Preprint at https://arxiv.org/abs/2411.14600 (2024).
Zhao, Y.-F. & Botana, A. S. Electronic structure of Ruddlesden-Popper nickelates: Strain to mimic the effects of pressure. Phys. Rev. B 111, 115154 (2025).
Lu, C., Pan, Z., Yang, F. & Wu, C. Interlayer-coupling-driven high-temperature superconductivity in La3Ni2O7 under pressure. Phys. Rev. Lett. 132, 146002 (2024).
Oh, H. & Zhang, Y.-H. Type-II t-J model and shared superexchange coupling from Hund’s rule in superconducting La3Ni2O7. Phys. Rev. B 108, 174511 (2023).
Cao, Y. & Yang, Y. Flat bands promoted by Hund’s rule coupling in the candidate double-layer high-temperature superconductor La3Ni2O7 under high pressure. Phys. Rev. B 109, L081105 (2024).
Qu, X.-Z. et al. Bilayer t-J-J⊥ model and magnetically mediated pairing in the pressurized nickelate La3Ni2O7. Phys. Rev. Lett. 132, 036502 (2024).
Ouyang, Z. et al. Hund electronic correlation in La3Ni2O7 under high pressure. Phys. Rev. B 109, 115114 (2024).
Wang, Z., Jiang, K. & Zhang, F.-C. Self-doped molecular Mott insulator for bilayer high-temperature superconducting La3Ni2O7. Preprint at https://arxiv.org/abs/2412.18469 (2025).
Botana, A. S., Lee, K.-W., Norman, M. R., Pardo, V. & Pickett, W. E. Low valence nickelates: launching the nickel age of superconductivity. Front. Phys. 9, 813532 (2022).
Luo, Z., Hu, X., Wang, M., Wú, W. & Yao, D.-X. Bilayer two-orbital model of La3Ni2O7 under pressure. Phys. Rev. Lett. 131, 126001 (2023).
Fan, Z. et al. Superconductivity in nickelate and cuprate superconductors with strong bilayer coupling. Phys. Rev. B 110, 024514 (2024).
Jiang, K., Wang, Z. & Zhang, F.-C. High-temperature superconductivity in La3Ni2O7. Chinese Phys. Lett. 41, 017402 (2024).
Jiang, R., Hou, J., Fan, Z., Lang, Z.-J. & Ku, W. Pressure driven fractionalization of ionic spins results in cupratelike high-Tc superconductivity in La3Ni2O7. Phys. Rev. Lett. 132, 126503 (2024).
Harper, F. E. & Tinkham, M. The mixed state in superconducting thin films. Phys. Rev. 172, 441–450 (1968).
Harvey, S. P. et al. Evidence for nodal superconductivity in infinite-layer nickelates. Preprint at https://arxiv.org/abs/2201.12971 (2022).
Mihaly, L., Kendziora, C., Hartge, J., Mandrus, D. & Forro, L. High-pressure cell for oxygen annealing at elevated temperatures. Rev. Sci. Instrum. 64, 2397 (1993).
Acknowledgements
We thank Y. Deng, K. Lee, Y. Lee, Y. Lv, J. May-Mann, F. Theuss, B. Y. Wang, Y.-M. Wu and J. J. Yu for discussions and assistance. Y.L., E.K.K., Y.T., J.L., S.R., Y.Y. and H.Y.H. acknowledge support from the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (contract no. DE-AC02-76SF00515), as well as SuperC and the Kavli Foundation (aspects of magnetic characterization). Work at the Stanford Nano Shared Facilities (SNSF) RRID:SCR_023230 is supported by the National Science Foundation under grant ECCS-1542152. L.B. and D.A.M. acknowledge support from the National Science Foundation (DMR-1719875), NSF PARADIM (DMR-2039380) and the Weill Institute and the Kavli Institute at Cornell University. X-ray measurements were carried out at the SSRL, SLAC National Accelerator Laboratory, supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences (contract no. DE-AC02-76SF00515). B.H.G. acknowledges support from the Max Planck Society and Schmidt Science Fellows in partnership with the Rhodes Trust.
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Y.Y. and H.Y.H. conceived and designed the project. Y.L. and E.K.K. synthesised the films. Y.Y. built the ozone annealing setup and studied the ozone annealing effects with Y.L. and Y.T. Y.L. characterized and studied the transport properties of films with the assistance of Y.T. L.B., B.H.G. and D.A.M. measured and analysed the STEM images. J.L., Y.L., Y.T. and V.T. performed the reciprocal-space mapping measurements. Y.Y., Y.L., S.R. and H.Y.H. analysed the data and wrote the paper with input from all authors.
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Extended data
Extended Data Fig. 1 Diamagnetic response for sample P236 and comparison with previous reports.
a, Normalized real part (Re(Vp)) and b, imaginary (Im(Vp)) part of the voltage in the pickup coil as a function of temperature, measured using a two-coil mutual-inductance technique on sample P236. c, Resistivity of the sample. For comparison, corresponding data from refs. 9 and 10, measured on La3Ni2O7 and (La,Pr)3Ni2O7 films, are also plotted. The red triangles in b and c mark the onset temperature of diamagnetic response and zero resistance Tc, respectively.
Extended Data Fig. 2 Structural properties of sample P75.
a, Synchrotron x-ray RSM of sample P75 on substrate SLAO(001). The (1117) Bragg peak of the film is measured along with the SLAO(109) Bragg peak. b, Tc,onset versus in-plane lattice constant. The bulk and thin film studies from ref. 9 are plotted for comparison.
Extended Data Fig. 3 ρ(T) of films with different growth and ozone annealing conditions.
a, ρ(T) of films grown at different p(O2), with ozone annealing conditions as described in ref. 9. b, ρ(T) of films annealed at varying Tanneal but the same w(O3). c, ρ(T) of films annealed at varying w(O3) but the same Tanneal. In each plot, the sample with the highest Tc,onset is highlighted with a thick line.
Extended Data Fig. 4 Bespoke ozone annealing setup with in situ electrical transport.
a, Schematic of the ozone annealing setup. b, Photograph of the setup, with an inset showing a film in the chip carrier inside the quartz tube. To the right of the chip carrier, a PT1000 sensor is positioned to measure the temperature at the chip carrier. c, Interior of the ozone generator, consisting of a tunable high voltage module (front), an ozone quartz generator with inlet and outlet (centre), and a cooling fan (back). A power meter is connected to the high voltage module to monitor the power which regulates w(O3).
Extended Data Fig. 5 Optimized ozone annealing profiles for sample P75.
a-c, Time-dependent profiles of ρ, w(O3), and Tanneal during optimized ozone annealing. The inset of a shows the saturation of ρ upon oxygenation completion. Blue vertical dashed lines mark changes in w(O3), while red vertical dashed lines indicate the start of warming, reaching Tanneal, and the completion of annealing, respectively. The complex evolution of ρ with time can be understood by changes in the oxidation environment during the annealing process. This is due to both the time required for the gas environment inside the quartz tube to respond after manually adjusting w(O3), and the temperature change.
Extended Data Fig. 6 Optimal timing of ozone annealing.
a-b, time-dependent resistivity measurements during ozone annealing of two specimens from the same growth (Sample P237). The triangles indicate the points at which the samples began cooling. In a, resistivity did not reach saturation before cooling, whereas in constrast to b. c, ρ(T) of the specimens shown in a and b.
Extended Data Fig. 7 Stability study.
a, XRD θ–2θ symmetric scan of as-grown films right after growth and five months later. b, Resistivity versus temperature ρ(T) for two specimens of sample P75: One piece was ozone-annealed immediately after growth, while the other was ozone-annealed five months later. c and d, Time-dependent ρ(T) plots of ozone-annealed samples P80 (stored in ambient conditions) and P75 (stored in liquid nitrogen dewar), respectively. e, Time-dependent resistivity at 300 K, normalized by the resistivity at day 0, for samples stored under different conditions. f, A photograph of Swagelok® cap and nut that is used as a gas-tight container to store samples in a nitrogen dewar.
Extended Data Fig. 8 Hall resistance (Rxy) versus magnetic field.
Data are anti-symmetrised. Data below 60 K shows non-linear behaviour due to the onset of superconductivity. a-c correspond to samples P75, P78, and P108, respectively. Data from Fig. 4b in the main text.
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Liu, Y., Ko, E.K., Tarn, Y. et al. Superconductivity and normal-state transport in compressively strained La2PrNi2O7 thin films. Nat. Mater. (2025). https://doi.org/10.1038/s41563-025-02258-y
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DOI: https://doi.org/10.1038/s41563-025-02258-y
