Superconductivity in Sr-doped La3Ni2O7 thin films
Source abstract
Abstract
Recent studies have demonstrated ambient pressure superconductivity in compressively strained La3Ni2O7 thin films, yet the phase diagram of heterovalent doping-critical for advancing the field-remains underexplored. Here we report superconductivity in Sr2+-doped La3-xSrxNi2O7 films. The superconducting transition temperature (Tc) follows an incomplete dome-like profile, maintaining similar Tc values across a wide doping range (0 ≤ x ≤ 0.21) before diminishing near x ≈ 0.38. Optimally doped films achieve a Tc value of ~42 K, with a high critical current (Jc > 1.4 kA cm-2 at 2 K) and upper critical fields (μ0Hc,∥(0) = 83.7 T, μ0Hc,⟂(0) = 110.3 T). Scanning transmission electron microscopy reveals that oxygen vacancies predominantly occupy planar NiO2 sites-unlike apical-site vacancies in bulk samples-due to compressive strain. Additionally, the elongated out-of-plane Ni-O bonds, exceeding those in pressurized bulk samples by 4%, likely weaken the interlayer d z 2 coupling and contribute to the reduced Tc in strained films.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Magnetic and transport properties of perovskites and related materials · Physics of Superconductivity and Magnetism · Electronic and Structural Properties of Oxides
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (60)
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. Phys. Rev. X 14, 011040 (2024).
5. Wang, N. et al. Bulk high-temperature superconductivity in pressurized tetragonal La2PrNi2O7. Nature 634, 579–584 (2024).10.1038/s41586-024-07996-8 ↗
6. Zhu, Y. et al. Superconductivity in pressurized trilayer La4Ni3O10−δ single crystals. Nature 631, 531–536 (2024).10.1038/s41586-024-07553-3 ↗
7. Wang, M., Wen, H.-H., Wu, T., Yao, D.-X. & Xiang, T. Normal and superconducting properties of La3Ni2O7. Chin. Phys. Lett. 41, 077402 (2024).10.1088/0256-307X/41/7/077402 ↗
8. 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).
9. Li, Q. et al. Signature of superconductivity in pressurized La4Ni3O10. Chin. Phys. Lett. 41, 017401 (2024).10.1088/0256-307X/41/1/017401 ↗
10. Sakakibara, H. et al. Theoretical analysis on the possibility of superconductivity in the trilayer Ruddlesden-Popper nickelate La4Ni3O10 under pressure and its experimental examination: comparison with La3Ni2O7. Phys. Rev. B 109, 144511 (2024).10.1103/PhysRevB.109.144511 ↗
11. Zhang, M. et al. Superconductivity in trilayer nickelate La4Ni3O10 under pressure. Phys. Rev. X 15, 021005 (2025).
12. Zhang, M. et al. Effects of pressure and doping on Ruddlesden-Popper phases Lan+1NinO3n+1. J. Mater. Sci. Technol. 185, 147–154 (2024).10.1016/j.jmst.2023.11.011 ↗
13. Feng, J.-J. et al. Unaltered density wave transition and pressure-induced signature of superconductivity in Nd-doped La3Ni2O7. Phys. Rev. B 110, L100507 (2024).10.1103/PhysRevB.110.L100507 ↗
14. 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 ↗
15. 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 ↗
16. 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 ↗
17. 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).10.1021/jacs.3c14052 ↗
18. Puphal, P. et al. Unconventional crystal structure of the high-pressure superconductor La3Ni2O7. Phys. Rev. Lett. 133, 146002 (2024).10.1103/PhysRevLett.133.146002 ↗
19. 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).10.1021/acs.inorgchem.3c04474 ↗
20. Li, F. et al. Ambient pressure growth of bilayer nickelate single crystals with superconductivity over 90 K under high pressure. Preprint at https://arxiv.org/abs/2501.14584 (2025).
21. Dagotto, E. Complexity in strongly correlated electronic systems. Science 309, 257–262 (2005).10.1126/science.1107559 ↗
22. 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 ↗
23. Taillefer, L. Scattering and pairing in cuprate superconductors. Annu. Rev. Condens. Matter Phys. 1, 51–70 (2010).10.1146/annurev-conmatphys-070909-104117 ↗
24. 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 ↗
25. Hussey, N. E. Phenomenology of the normal state in-plane transport properties of high-Tc cuprates. J. Phys. Condens. Matter 20, 123201 (2008).10.1088/0953-8984/20/12/123201 ↗
26. Yang, J. et al. Orbital-dependent electron correlation in double-layer nickelate La3Ni2O7. Nat. Commun. 15, 4373 (2024).
27. 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).10.1103/PhysRevB.108.L201121 ↗
28. 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 ↗
29. 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).
30. 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 ↗
31. 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 ↗
32. 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 ↗
33. 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 ↗
34. Le, C., Zhan, J., Wu, X. & Hu, J. Landscape of correlated orders in strained bilayer nickelate thin films. Preprint at https://arxiv.org/abs/2501.14665 (2025).
35. Shao, Z.-Y., Liu, Y.-B., Liu, M. & Yang, F. Band structure and pairing nature of La3Ni2O7 thin film at ambient pressure. Phys. Rev. B 112, 024506 (2025).10.1103/9t6n-jqr5 ↗
36. Yue, C. et al. Correlated electronic structures and unconventional superconductivity in bilayer nickelate heterostructures. Natl. Sci. Rev. nwaf253 (2025).10.1093/nsr/nwaf253 ↗
37. Shi, H. et al. The effect of carrier doping and thickness on the electronic structures of La3Ni2O7 thin films. Chin. Phys. Lett. 42, 080708 (2025).10.1088/0256-307X/42/8/080708 ↗
38. Jiao, K. et al. Enhanced conductivity in Sr doped La3Ni2O7-δ with high-pressure oxygen annealing. Phys. C 621, 1354504 (2024).10.1016/j.physc.2024.1354504 ↗
39. Xu, M. et al. Pressure-dependent “Insulator–Metal–Insulator” behavior in Sr-doped La3Ni2O7. Adv. Electron. Mater. 10, 2400078 (2024).10.1002/aelm.202400078 ↗
40. Liu, Y., Ou, M., Wang, Y. & Wen, H.-H. Temperature-independent Hall coefficient in hole-doped La3Ni2O7 thin films: evidence for single-band transport. J. Phys. Condens. Matter 37, 255502 (2025).10.1088/1361-648X/ade10b ↗
41. Kim, J. et al. Defect engineering in A2BO4 thin films via surface-reconstructed LaSrAlO4 substrates. Small Methods 6, 2200880 (2022).
42. 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 ↗
43. 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 ↗
44. Hsu, Y.-T. et al. Transport phase diagram and anomalous metallicity in superconducting infinite-layer nickelates. Nat. Commun. 15, 9863 (2024).
45. Lee, K. et al. Linear-in-temperature resistivity for optimally superconducting (Nd,Sr)NiO2. Nature 619, 288–292 (2023).10.1038/s41586-023-06129-x ↗
46. Cooper, R. A. et al. Anomalous criticality in the electrical resistivity of La2–xSrxCuO4. Science 323, 603–607 (2009).10.1126/science.1165015 ↗
47. Wang, B. Y. et al. Electronic structure of compressively strained thin film La2PrNi2O7. Preprint at https://arxiv.org/abs/2504.16372 (2025).
48. Li, D. et al. Superconducting dome in Nd1–xSrxNiO2 infinite layer films. Phys. Rev. Lett. 125, 027001 (2020).10.1103/PhysRevLett.125.027001 ↗
49. Zeng, S. et al. Phase diagram and superconducting dome of infinite-layer Nd1–xSrxNiO2 thin films. Phys. Rev. Lett. 125, 147003 (2020).10.1103/PhysRevLett.125.147003 ↗
50. Song, Q. et al. Antiferromagnetic metal phase in an electron-doped rare-earth nickelate. Nat. Phys. 19, 522–528 (2023).10.1038/s41567-022-01907-2 ↗
51. Biswas, A. et al. Selective A- or B-site single termination on surfaces of layered oxide SrLaAlO4. Appl. Phys. Lett. 102, 051603 (2013).10.1063/1.4790575 ↗
52. Lee, J. H. et al. Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy. Nat. Mater. 13, 879–883 (2014).10.1038/nmat4039 ↗
53. Nie, Y. F. et al. Atomically precise interfaces from non-stoichiometric deposition. Nat. Commun. 5, 4530 (2014).
54. Nord, M., Vullum, P. E., MacLaren, I., Tybell, T. & Holmestad, R. Atomap: a new software tool for the automated analysis of atomic resolution images using two-dimensional Gaussian fitting. Adv. Struct. Chem. Imaging 3, 9 (2017).10.1186/s40679-017-0042-5 ↗
55. Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).10.1016/0927-0256(96)00008-0 ↗
56. 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 ↗
57. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).10.1103/PhysRevB.50.17953 ↗
58. Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999).10.1103/PhysRevB.59.1758 ↗
59. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).10.1103/PhysRevLett.77.3865 ↗
60. Ling, C. D., Argyriou, D. N., Wu, G. & Neumeier, J. J. Neutron diffraction study of La3Ni2O7: structural relationships among n = 1, 2, and 3 phases Lan+1NinO3n+1. J. Solid State Chem. 152, 517–525 (2000).10.1006/jssc.2000.8721 ↗