Interstitial oxygen order and its competition with superconductivity in La2PrNi2O7+δ
Source abstract
Abstract
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.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Magnetic and transport properties of perovskites and related materials · Advanced Condensed Matter Physics · Physics of Superconductivity and Magnetism
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (69)
Show source-provided references
1. Sun, H. et al. Signatures of superconductivity near 80 K in a nickelate under high pressure. Nature 621, 493–498 (2023).10.1038/s41586-023-06408-7 ↗
2. Hou, J. et al. Emergence of high-temperature superconducting phase in pressurized La3Ni2O7 crystals. Chin. Phys. Lett. 40, 117302 (2023).10.1088/0256-307X/40/11/117302 ↗
3. Zhang, Y. et al. High-temperature superconductivity with zero resistance and strange-metal behaviour in La3Ni2O7–δ. Nat. Phys. 20, 1269–1273 (2024).10.1038/s41567-024-02515-y ↗
4. Wang, G. et al. Pressure-induced superconductivity in polycrystalline La3Ni2O7–δ. Phys. Rev. X 14, 011040 (2024).
5. Li, J. et al. Identification of superconductivity in bilayer nickelate La3Ni2O7 under high pressure up to 100 GPa. Natl Sci. Rev. 12, nwaf220 (2025).10.1093/nsr/nwaf220 ↗
6. 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).10.1063/5.0247684 ↗
7. Lee, P. A., Nagaosa, N. & Wen, X.-G. Doping a Mott insulator: physics of high-temperature superconductivity. Rev. Mod. Phys. 78, 17–85 (2006).10.1103/RevModPhys.78.17 ↗
8. Keimer, B., Kivelson, S. A., Norman, M. R., Uchida, S. & Zaanen, J. From quantum matter to high-temperature superconductivity in copper oxides. Nature 518, 179–186 (2015).10.1038/nature14165 ↗
9. 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).10.1103/PhysRevLett.131.126001 ↗
10. Christiansson, V., Petocchi, F. & Werner, P. Correlated electronic structure of La3Ni2O7 under pressure. Phys. Rev. Lett. 131, 206501 (2023).10.1103/PhysRevLett.131.206501 ↗
11. Yang, Q.-G., Wang, D. & Wang, Q.-H. Possible s±-wave superconductivity in La3Ni2O7. Phys. Rev. B 108, L140505 (2023).10.1103/PhysRevB.108.L140505 ↗
12. 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).10.1103/PhysRevB.108.174511 ↗
13. Yang, J. et al. Orbital-dependent electron correlation in double-layer nickelate La3Ni2O7. Nat. Commun. 15, 4373 (2024).10.1038/s41467-024-48701-7 ↗
14. Liu, Z. et al. Electronic correlations and partial gap in the bilayer nickelate La3Ni2O7. Nat. Commun. 15, 7570 (2024).10.1038/s41467-024-52001-5 ↗
15. Lu, C., Pan, Z., Yang, F. & Wu, C. Interlayer coupling driven high-temperature superconductivity in La3Ni2O7 under pressure. Phys. Rev. Lett. 132, 146002 (2024).10.1103/PhysRevLett.132.146002 ↗
16. 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).10.1103/PhysRevLett.132.036502 ↗
17. 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).10.1103/PhysRevLett.132.106002 ↗
18. Chen, Y., Tian, Y.-H., Wang, J.-M., He, R.-Q. & Lu, Z.-Y. Non-Fermi liquid and antiferromagnetic correlations with hole doping in the bilayer two-orbital Hubbard model of La3Ni2O7 at zero temperature. Phys. Rev. B 110, 235119 (2024).10.1103/PhysRevB.110.235119 ↗
19. Wang, N. et al. Bulk high-temperature superconductivity in pressurized tetragonal La2PrNi2O7. Nature 634, 579–584 (2024).10.1038/s41586-024-07996-8 ↗
20. 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).10.1021/jacs.3c13094 ↗
21. Wang, G. et al. Chemical versus physical pressure effects on the structure transition of bilayer nickelates. NPJ Quantum Mater 10, 1 (2025).10.1038/s41535-024-00721-8 ↗
22. Ko, E. K. et al. Signatures of ambient pressure superconductivity in thin film La3Ni2O7. Nature 638, 935–940 (2025).10.1038/s41586-024-08525-3 ↗
23. Zhou, G. et al. Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films. Nature 640, 641–646 (2025).10.1038/s41586-025-08755-z ↗
24. Liu, Y. et al. Superconductivity and normal-state transport in compressively strained La2PrNi2O7 thin films. Nat. Mater. 24, 1221–1227 (2025).10.1038/s41563-025-02258-y ↗
25. Shi, M. et al. Prerequisite of superconductivity: SDW rather than tetragonal structure in double-layer La3Ni2O7–x. Preprint at https://arxiv.org/abs/2501.14202 (2025).
26. Tranquada, J. M., Sternlieb, B. J., Axe, J. D., Nakamura, Y. & Uchida, S. Evidence for stripe correlations of spins and holes in copper oxide superconductors. Nature 375, 561–563 (1995).10.1038/375561a0 ↗
27. Emery, V. J., Kivelson, S. A. & Tranquada, J. M. Stripe phases in high-temperature superconductors. Proc. Natl Acad. Sci. USA 96, 8814–8817 (1999).10.1073/pnas.96.16.8814 ↗
28. Kivelson, S. A. et al. How to detect fluctuating stripes in the high-temperature superconductors. Rev. Mod. Phys. 75, 1201–1241 (2003).10.1103/RevModPhys.75.1201 ↗
29. Jiang, Y. et al. Electron ptychography of 2D materials to deep sub-ångström resolution. Nature 559, 343–349 (2018).10.1038/s41586-018-0298-5 ↗
30. Chen, Z. et al. Electron ptychography achieves atomic-resolution limits set by lattice vibrations. Science 372, 826–831 (2021).10.1126/science.abg2533 ↗
31. Ikeda, A., Krockenberger, Y., Irie, H., Naito, M. & Yamamoto, H. Direct observation of infinite NiO2 planes in LaNiO2 films. Appl. Phys. Express 9, 061101 (2016).10.7567/APEX.9.061101 ↗
32. Dong, Z. et al. Visualization of oxygen vacancies and self-doped ligand holes in La3Ni2O7−δ. Nature 630, 847–852 (2024).10.1038/s41586-024-07482-1 ↗
33. Zambon, P. et al. KITE: high frame rate, high count rate pixelated electron counting ASIC for 4D STEM applications featuring high-Z sensor. Nucl. Instrum. Methods Phys. Res.A 1048, 167888 (2023).10.1016/j.nima.2022.167888 ↗
34. Lee, D. & Lee, H. N. Controlling oxygen mobility in Ruddlesden–Popper oxides. Materials 10, 368 (2017).10.3390/ma10040368 ↗
35. Nirala, G., Yadav, D. & Upadhyay, S. Ruddlesden-Popper phase A2BO4 oxides: recent studies on structure, electrical, dielectric, and optical properties. J. Adv. Ceram. 9, 129–148 (2020).10.1007/s40145-020-0365-x ↗
36. Tarutin, A. P., Lyagaeva, J. G., Medvedev, D. A., Bi, L. & Yaremchenko, A. A. Recent advances in layered Ln2NiO4+δ nickelates: fundamentals and prospects of their applications in protonic ceramic fuel and electrolysis cells. J. Mater. Chem. A 9, 154–195 (2021).10.1039/D0TA08132A ↗
37. Tranquada, J. M., Buttrey, D. J., Sachan, V. & Lorenzo, J. E. Simultaneous ordering of holes and spins in La2NiO4.125. Phys. Rev. Lett. 73, 1003–1006 (1994).10.1103/PhysRevLett.73.1003 ↗
38. Tranquada, J. M. et al. Oxygen intercalation, stage ordering, and phase separation in La2NiO4+δ with 0.05 ≲ δ ≲ 0.11. Phys. Rev. B 50, 6340–6351 (1994).10.1103/PhysRevB.50.6340 ↗
39. Wells, B. O. et al. Incommensurate spin fluctuations in high-transition temperature superconductors. Science 277, 1067–1071 (1997).10.1126/science.277.5329.1067 ↗
40. Rhodes, L. C. & Wahl, P. Structural routes to stabilize superconducting La3Ni2O7 at ambient pressure. Phys. Rev. Mater. 8, 044801 (2024).10.1103/PhysRevMaterials.8.044801 ↗
41. Bhatt, L. et al. Resolving structural origins for superconductivity in strain-engineered La3Ni2O7 thin films. Preprint at https://arxiv.org/abs/2501.08204 (2025).
42. 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).10.1103/PhysRevLett.131.236002 ↗
43. 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).10.1103/PhysRevB.108.L201108 ↗
44. 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).10.1103/PhysRevB.108.L140504 ↗
45. Wang, J. & Yang, Y. Highly asymmetric superconducting dome and strange metallicity in La3Ni2O7. Phys. Rev. B 111, 014512 (2025).10.1103/PhysRevB.111.014512 ↗
46. Chen, X. et al. Electronic and magnetic excitations in La3Ni2O7. Nat. Commun. 15, 9597 (2024).10.1038/s41467-024-53863-5 ↗
47. Chen, K. et al. Evidence of spin density waves in La3Ni2O7–δ. Phys. Rev. Lett. 132, 256503 (2024).10.1103/PhysRevLett.132.256503 ↗
48. Khasanov, R. et al. Pressure-enhanced splitting of density wave transitions in La3Ni2O7–δ. Nat. Phys. 21, 430–436 (2025).10.1038/s41567-024-02754-z ↗
49. Zhao, D. et al. Pressure-enhanced spin-density-wave transition in double-layer nickelate La3Ni2O7−δ. Sci. Bull. 70, 1239–1245 (2025).10.1016/j.scib.2025.02.019 ↗
50. Li, M. et al. Orbital signatures of density wave transition in La3Ni2O7–δ and La2PrNi2O7–δ RP-nickelates probed via in-situ X-ray absorption near-edge spectroscopy. Preprint at https://arxiv.org/abs/2502.10962 (2025).
51. Rodríguez-Carvajal, J. Recent advances in magnetic structure determination by neutron powder diffraction. Phys. B Condens. Matter 192, 55–69 (1993).10.1016/0921-4526(93)90108-I ↗
52. Tsai, E. H. R., Usov, I., Diaz, A., Menzel, A. & Guizar-Sicairos, M. X-ray ptychography with extended depth of field. Opt. Express 24, 29089–29108 (2016).10.1364/OE.24.029089 ↗
53. Zhang, F. et al. Translation position determination in ptychographic coherent diffraction imaging. Opt. Express 21, 13592–13606 (2013).10.1364/OE.21.013592 ↗
54. Thibault, P. & Menzel, A. Reconstructing state mixtures from diffraction measurements. Nature 494, 68–71 (2013).10.1038/nature11806 ↗
55. Chen, Z. et al. Mixed-state electron ptychography enables sub-angstrom resolution imaging with picometer precision at low dose. Nat. Commun. 11, 2994 (2020).10.1038/s41467-020-16688-6 ↗
56. Clark, J. N., Huang, X., Harder, R. & Robinson, I. K. High-resolution three-dimensional partially coherent diffraction imaging. Nat. Commun. 3, 993 (2012).10.1038/ncomms1994 ↗
57. Xu, W. et al. A high-performance reconstruction method for partially coherent ptychography. Ultramicroscopy 267, 114068 (2024).10.1016/j.ultramic.2024.114068 ↗
58. Thibault, P. & Guizar-Sicairos, M. Maximum-likelihood refinement for coherent diffractive imaging. New J. Phys. 14, 063004 (2012).10.1088/1367-2630/14/6/063004 ↗
59. Odstrčil, M., Menzel, A. & Guizar-Sicairos, M. Iterative least-squares solver for generalized maximum-likelihood ptychography. Opt. Express 26, 3108–3123 (2018).10.1364/OE.26.003108 ↗
60. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).10.1103/PhysRevB.54.11169 ↗
61. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).10.1103/PhysRevB.50.17953 ↗
62. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).10.1103/PhysRevLett.77.3865 ↗
63. Perdew, J. P. et al. Restoring the density-gradient expansion for exchange in solids and surfaces. Phys. Rev. Lett. 100, 136406 (2008).10.1103/PhysRevLett.100.136406 ↗
64. Sakakibara, H. et al. Model construction and a possibility of cupratelike pairing in a new d9 nickelate superconductor (Nd,Sr)NiO2. Phys. Rev. Lett. 125, 077003 (2020).10.1103/PhysRevLett.125.077003 ↗
65. Huo, Z. et al. First-principles study of the Pr-doped bilayer nickelate La3Ni2O7. Phys. Rev. B 111, 195118 (2025).10.1103/PhysRevB.111.195118 ↗
66. Bellaiche, L. & Vanderbilt, D. Virtual crystal approximation revisited: application to dielectric and piezoelectric properties of perovskites. Phys. Rev. B 61, 7877–7882 (2000).10.1103/PhysRevB.61.7877 ↗
67. Hetényi, B., De Angelis, F., Giannozzi, P. & Car, R. Calculation of near-edge X-ray-absorption fine structure at finite temperatures: spectral signatures of hydrogen bond breaking in liquid water. J. Chem. Phys. 120, 8632–8637 (2004).10.1063/1.1703526 ↗
68. Karsai, F., Humer, M., Flage-Larsen, E., Blaha, P. & Kresse, G. Effects of electron-phonon coupling on absorption spectrum: K edge of hexagonal boron nitride. Phys. Rev. B 98, 235205 (2018).10.1103/PhysRevB.98.235205 ↗
69. Dong, Z., Wang, Y. & Chen, Z. Dataset for: interstitial oxygen order and its competition with superconductivity in La2PrNi2O7+δ. Zenodo https://doi.org/10.5281/zenodo.15666415 (2025).10.5281/zenodo.15666415 ↗