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Resolving the polar interface of infinite-layer nickelate thin films

Nature Materials volume 22, pages 466–473 (2023)Cite this article

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Abstract

Nickel-based superconductors provide a long-awaited experimental platform to explore possible cuprate-like superconductivity. Despite similar crystal structure and d electron filling, however, superconductivity in nickelates has thus far only been stabilized in thin-film geometry, raising questions about the polar interface between substrate and thin film. Here we conduct a detailed experimental and theoretical study of the prototypical interface between Nd1−xSrxNiO2 and SrTiO3. Atomic-resolution electron energy loss spectroscopy in the scanning transmission electron microscope reveals the formation of a single intermediate Nd(Ti,Ni)O3 layer. Density functional theory calculations with a Hubbard U term show how the observed structure alleviates the polar discontinuity. We explore the effects of oxygen occupancy, hole doping and cation structure to disentangle the contributions of each for reducing interface charge density. Resolving the non-trivial interface structure will be instructive for future synthesis of nickelate films on other substrates and in vertical heterostructures.

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Fig. 1: Intermediate atomic layer between nickelate film and substrate.
Fig. 2: Model interface charge accumulation.
Fig. 3: Experimental measurement of electronic structure across the interface.
Fig. 4: Impact of Sr doping on oxygen removal energy.
Fig. 5: Impact of Sr doping on interfacial charge accumulation.
Fig. 6: Full lattice and electronic structure of the nickelate–substrate interface.

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Data availability

The experimental data relevant to the findings of this paper have been deposited in the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM) database at https://doi.org/10.34863/nf7t-jj61. Additional data, including that contained in Supplementary Information and results of the DFT + U calculations, are available upon reasonable request to the authors.

References

  1. Li, D. et al. Superconductivity in an infinite-layer nickelate. Nature 572, 624–627 (2019).

    Article  CAS  Google Scholar 

  2. Zeng, S. et al. Phase diagram and superconducting dome of infinite-layer Nd1−xSrxNiO2 thin films. Phys. Rev. Lett. 125, 147003 (2020).

    Article  CAS  Google Scholar 

  3. Gu, Q. et al. Single particle tunneling spectrum of superconducting Nd1−xSrxNiO2 thin films. Nat. Commun. 11, 6027 (2020).

    Article  CAS  Google Scholar 

  4. Osada, M. et al. A superconducting praseodymium nickelate with infinite layer structure. Nano Lett. 20, 5735–5740 (2020).

    Article  CAS  Google Scholar 

  5. Zeng, S. et al. Superconductivity in infinite-layer nickelate La1−xCaxNiO2 thin films. Sci. Adv. 8, eabl9927 (2022).

    Article  CAS  Google Scholar 

  6. Osada, M. et al. Nickelate superconductivity without rare-earth magnetism: (La,Sr)NiO2. Adv. Mater. 33, 2104083 (2021).

    Article  CAS  Google Scholar 

  7. Gao, Q., Zhao, Y., Zhou, X. & Zhu, Z. Preparation of superconducting thin films of infinite-layer nickelate Nd0.8Sr0.2NiO2. Chin. Phys. Lett. 38, 077401 (2021).

    Article  CAS  Google Scholar 

  8. Hepting, M. et al. Electronic structure of the parent compound of superconducting infinite-layer nickelates. Nat. Mater. 19, 381–385 (2020).

    Article  CAS  Google Scholar 

  9. Goodge, B. H. et al. Doping evolution of the Mott–Hubbard landscape in infinite-layer nickelates. Proc. Natl Acad. Sci. USA 118, e2007683118 (2021).

    Article  CAS  Google Scholar 

  10. Bernardini, F. & Cano, A. Stability and electronic properties of LaNiO2/SrTiO3 heterostructures. J. Phys. Mater. 3, 03LT01 (2020).

    Article  CAS  Google Scholar 

  11. Geisler, B. & Pentcheva, R. Fundamental difference in the electronic reconstruction of infinite-layer versus perovskite neodymium nickelate films on SrTiO3 (001). Phys. Rev. B 102, 020502 (2020).

    Article  CAS  Google Scholar 

  12. Bednorz, J. G. & Müller, K. A. Possible high Tc superconductivity in the Ba-La-Cu-O system. Z. Phys. B Condens. Matter 64, 189–193 (1986).

    Article  CAS  Google Scholar 

  13. Wu, M.-K. et al. Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure. Phys. Rev. Lett. 58, 908 (1987).

    Article  CAS  Google Scholar 

  14. Maeda, H., Tanaka, Y., Fukutomi, M. & Asano, T. A new high-Tc oxide superconductor without a rare earth element. Jpn. J. Appl. Phys. 27, L209 (1988).

    Article  CAS  Google Scholar 

  15. Sheng, Z. & Hermann, A. Bulk superconductivity at 120 K in the Tl–Ca/Ba–Cu–O system. Nature 332, 138–139 (1988).

    Article  CAS  Google Scholar 

  16. Schilling, A., Cantoni, M., Guo, J. & Ott, H. Superconductivity above 130 K in the Hg–Ba–Ca–Cu–O system. Nature 363, 56–58 (1993).

    Article  CAS  Google Scholar 

  17. Pan, G. A. et al. Superconductivity in a quintuple-layer square-planar nickelate. Nat. Mater. 21, 160–164 (2022).

    Article  CAS  Google Scholar 

  18. Ren, X. et al. Strain-induced enhancement of Tc in infinite-layer Pr0.8Sr0.2NiO2 films. Preprint at https://arxiv.org/abs/2109.05761 (2022).

  19. Lee, K. et al. Aspects of the synthesis of thin film superconducting infinite-layer nickelates. APL Mater. 8, 041107 (2020).

    Article  CAS  Google Scholar 

  20. Puphal, P. et al. Topotactic transformation of single crystals: from perovskite to infinite-layer nickelates. Sci. Adv. 7, eabl8091 (2021).

    Article  CAS  Google Scholar 

  21. Zhang, Y. et al. Similarities and differences between nickelate and cuprate films grown on a SrTiO3 substrate. Phys. Rev. B 102, 195117 (2020).

    Article  CAS  Google Scholar 

  22. He, R. et al. Polarity-induced electronic and atomic reconstruction at NdNiO2/SrTiO3 interfaces. Phys. Rev. B 102, 035118 (2020).

    Article  CAS  Google Scholar 

  23. Geisler, B. & Pentcheva, R. Correlated interface electron gas in infinite-layer nickelate versus cuprate films on SrTiO3 (001). Phys. Rev. Res. 3, 013261 (2021).

    Article  CAS  Google Scholar 

  24. Mundy, J. A. et al. Visualizing the interfacial evolution from charge compensation to metallic screening across the manganite metal–insulator transition. Nat. Commun. 5, 3464 (2014).

    Article  Google Scholar 

  25. Ohtomo, A. & Hwang, H. Y. A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427, 423–426 (2004).

    Article  CAS  Google Scholar 

  26. Reyren, N. et al. Superconducting interfaces between insulating oxides. Science 317, 1196–1199 (2007).

    Article  CAS  Google Scholar 

  27. Lee, K. et al. Character of the “normal state” of the nickelate superconductors. Preprint at https://arxiv.org/abs/2203.02580 (2022).

  28. Botana, A. S., Bernardini, F. & Cano, A. Nickelate superconductors: an ongoing dialog between theory and experiments. J. Exp. Theor. Phys. 132, 618–627 (2021).

    Article  CAS  Google Scholar 

  29. Nakagawa, N., Hwang, H. Y. & Muller, D. A. Why some interfaces cannot be sharp. Nat. Mater. 5, 204–209 (2006).

    Article  CAS  Google Scholar 

  30. Kourkoutis, L. F., Muller, D., Hotta, Y. & Hwang, H. Asymmetric interface profiles in LaVO3/SrTiO3 heterostructures grown by pulsed laser deposition. Appl. Phys. Lett. 91, 163101 (2007).

    Article  Google Scholar 

  31. Kourkoutis, L. F., Song, J., Hwang, H. & Muller, D. Microscopic origins for stabilizing room-temperature ferromagnetism in ultrathin manganite layers. Proc. Natl Acad. Sci. USA 107, 11682–11685 (2010).

    Article  CAS  Google Scholar 

  32. Egerton, R. Oscillator-strength parameterization of inner-shell cross sections. Ultramicroscopy 50, 13–28 (1993).

    Article  CAS  Google Scholar 

  33. Ohtomo, A., Muller, D. A., Grazul, J. L. & Hwang, H. Y. Artificial charge-modulation in atomic-scale perovskite titanate superlattices. Nature 419, 378–380 (2002).

    Article  CAS  Google Scholar 

  34. Zhou, X.-R. et al. Negligible oxygen vacancies, low critical current density, electric-field modulation, in-plane anisotropic and high-field transport of a superconducting Nd0.8Sr0.2NiO2/SrTiO3 heterostructure. Rare Metals 40, 2847–2854 (2021).

    Article  CAS  Google Scholar 

  35. Sahinovic, A. & Geisler, B. Active learning and element embedding approach in neural networks for infinite-layer versus perovskite oxides. Phys. Rev. Res. 3, L042022 (2021).

    Article  CAS  Google Scholar 

  36. de Groot, F. M. F. et al. Oxygen 1s x-ray-absorption edges of transition-metal oxides. Phys. Rev. B 40, 5715–5723 (1989).

    Article  Google Scholar 

  37. Kourkoutis, L. F. et al. Atomic-resolution spectroscopic imaging of oxide interfaces. Philos. Mag. 90, 4731–4749 (2010).

    Article  CAS  Google Scholar 

  38. De Groot, F. et al. Oxygen 1s x-ray absorption of tetravalent titanium oxides: a comparison with single-particle calculations. Phys. Rev. B 48, 2074 (1993).

    Article  Google Scholar 

  39. Suntivich, J. et al. Estimating hybridization of transition metal and oxygen states in perovskites from O K-edge X-ray absorption spectroscopy. J. Phys. Chem. C 118, 1856–1863 (2014).

    Article  CAS  Google Scholar 

  40. Frati, F., Hunault, M. O. & De Groot, F. M. Oxygen k-edge X-ray absorption spectra. Chem. Rev. 120, 4056–4110 (2020).

    Article  CAS  Google Scholar 

  41. Li, D. et al. Superconducting dome in Nd1−xSrxNiO2 infinite layer films. Phys. Rev. Lett. 125, 027001 (2020).

    Article  CAS  Google Scholar 

  42. Zeng, S. et al. Observation of perfect diamagnetism and interfacial effect on the electronic structures in infinite layer Nd0.8Sr0.2NiO2 superconductors. Nat. Commun. 13, 743 (2022).

    Article  CAS  Google Scholar 

  43. Lu, H. et al. Magnetic excitations in infinite-layer nickelates. Science 373, 213–216 (2021).

    Article  CAS  Google Scholar 

  44. Rossi, M. et al. A broken translational symmetry state in an infinite-layer nickelate. Nat. Phys. 18, 869–873 (2022).

    Article  CAS  Google Scholar 

  45. Krieger, G. et al. Charge and spin order dichotomy in NdNiO2 driven by the capping layer. Phys. Rev. Lett. 129, 027002 (2022).

    Article  CAS  Google Scholar 

  46. Tam, C. C. et al. Charge density waves in infinite-layer NdNiO2 nickelates. Nat. Mater. 21, 1116–1120 (2022).

    Article  CAS  Google Scholar 

  47. Ruf, J. P. et al. Strain-stabilized superconductivity. Nat. Commun. 12, 59 (2021).

    Article  CAS  Google Scholar 

  48. Hicks, C. W. et al. Strong increase of Tc of Sr2RuO4 under both tensile and compressive strain. Science 344, 283–285 (2014).

    Article  CAS  Google Scholar 

  49. Steppke, A. et al. Strong peak in Tc of Sr2RuO4 under uniaxial pressure. Science 355, eaaf9398 (2017).

    Article  Google Scholar 

  50. Nair, H. P. et al. Demystifying the growth of superconducting Sr2RuO4 thin films. APL Mater. 6, 101108 (2018).

    Article  Google Scholar 

  51. Wang, N. N. et al. Pressure-induced monotonic enhancement of Tc to over 30 K in the superconducting Pr0.82Sr0.18NiO2 thin films. Nat. Commun. 13, 4367 (2022).

    Article  CAS  Google Scholar 

  52. Ortiz, R. A. et al. Superlattice approach to doping infinite-layer nickelates. Phys. Rev. B 104, 165137 (2021).

    Article  CAS  Google Scholar 

  53. Lippmaa, M. et al. Observation of SrTiO3 step edge dynamics by real-time high-temperature STM. Appl. Surf. Sci. 130, 582–586 (1998).

    Article  Google Scholar 

  54. Nishimura, T., Ikeda, A., Namba, H., Morishita, T. & Kido, Y. Structure change of TiO2-terminated SrTiO3 (001) surfaces by annealing in O2 atmosphere and ultrahigh vacuum. Surf. Sci. 421, 273–278 (1999).

    Article  CAS  Google Scholar 

  55. Goodge, B. H., Bianco, E., Schnitzer, N., Zandbergen, H. W. & Kourkoutis, L. F. Atomic-resolution cryo-STEM across continuously variable temperatures. Microsc. Microanal. 26, 439–446 (2020).

    Article  CAS  Google Scholar 

  56. Savitzky, B. H. et al. Image registration of low signal-to-noise cryo-stem data. Ultramicroscopy 191, 56–65 (2018).

    Article  CAS  Google Scholar 

  57. Stetson, P. B. Daophot: a computer program for crowded-field stellar photometry. Publ. Astron. Soc. Pac. 99, 191 (1987).

    Article  Google Scholar 

  58. Kohn, W. & Sham, L. J. Self-consistent equations including exchange and correlation effects. Phys. Rev. 140, A1133 (1965).

    Article  Google Scholar 

  59. Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009).

    Article  Google Scholar 

  60. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865 (1996).

    Article  CAS  Google Scholar 

  61. Anisimov, V. I., Solovyev, I., Korotin, M., Czyżyk, M. & Sawatzky, G. Density-functional theory and NiO photoemission spectra. Phys. Rev. B 48, 16929 (1993).

    Article  CAS  Google Scholar 

  62. Cococcioni, M. & De Gironcoli, S. Linear response approach to the calculation of the effective interaction parameters in the LDA + U method. Phys. Rev. B 71, 035105 (2005).

    Article  Google Scholar 

  63. Liu, J. et al. Heterointerface engineered electronic and magnetic phases of NdNiO3 thin films. Nat. Commun. 4, 2714 (2013).

    Article  Google Scholar 

  64. Botana, A. A. & Norman, M. R. Similarities and differences between infinite-layer nickelates and cuprates and implications for superconductivity. Phys. Rev. X 10, 011024 (2020).

    CAS  Google Scholar 

  65. Vanderbilt, D. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys. Rev. B 41, 7892 (1990).

    Article  CAS  Google Scholar 

  66. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953 (1994).

    Article  Google Scholar 

  67. Nomura, Y. et al. Formation of a two-dimensional single-component correlated electron system and band engineering in the nickelate superconductor NdNiO2. Phys. Rev. B 100, 205138 (2019).

    Article  CAS  Google Scholar 

  68. Lechermann, F. Late transition metal oxides with infinite-layer structure: nickelates versus cuprates. Phys. Rev. B 101, 081110 (2020).

    Article  CAS  Google Scholar 

  69. Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188 (1976).

    Article  Google Scholar 

  70. Methfessel, M. & Paxton, A. High-precision sampling for Brillouin-zone integration in metals. Phys. Rev. B 40, 3616 (1989).

    Article  CAS  Google Scholar 

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Acknowledgements

B.H.G. and L.F.K. acknowledge support from the Department of Defense Air Force Office of Scientific Research (FA 9550-16-1-0305; L.F.K.) and the Packard Foundation. This work made use of the Cornell Center for Materials Research Shared Facilities, which are supported through the NSF MRSEC Program (DMR-1719875; L.F.K.). The FEI Titan Themis 300 was acquired with support from NSF (NSF-MRI-1429155; L.F.K.), with additional support from Cornell University, the Weill Institute and the Kavli Institute at Cornell. The Thermo Fisher Helios G4 UX focused ion beam was acquired with support from the National Science Foundation Platform for Accelerated Realization, Analysis, and Discovery of Interface Materials (Cooperative Agreement DMR-1539918; L.F.K.). B.G. and R.P. acknowledge support from the German Research Foundation (DFG) within CRC/TRR 80 (107745057; R.P.). Projects G3 and G8 and computational time at magnitUDE were granted by the Center for Computational Sciences and Simulation of the University of Duisburg-Essen (DFG Grant INST 20876/209-1 FUGG; R.P.). The work at SLAC/Stanford is supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (DE-AC02-76SF00515; H.Y.H.) and the Gordon and Betty Moore Foundation’s Emergent Phenomena in Quantum Systems Initiative (GBMF9072 for synthesis equipment; H.Y.H.). M.O. acknowledges partial financial support from the Takenaka Scholarship Foundation.

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Authors and Affiliations

  1. School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA

    Berit H. Goodge & Lena F. Kourkoutis

  2. Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, USA

    Berit H. Goodge & Lena F. Kourkoutis

  3. Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, Duisburg, Germany

    Benjamin Geisler & Rossitza Pentcheva

  4. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA

    Kyuho Lee, Motoki Osada, Bai Yang Wang, Danfeng Li & Harold Y. Hwang

  5. Department of Physics, Stanford University, Stanford, CA, USA

    Kyuho Lee & Bai Yang Wang

  6. Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA

    Motoki Osada

  7. Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA

    Danfeng Li

  8. Department of Physics, City University of Hong Kong, Kowloon, Hong Kong

    Danfeng Li

  9. Department of Applied Physics, Stanford University, Stanford, CA, USA

    Harold Y. Hwang

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Contributions

B.H.G. and L.F.K. conceived of the project. L.F.K., R.P. and H.Y.H. supervised the research. B.H.G. and L.F.K. performed the electron microscopy, electron energy loss spectroscopy and corresponding data analysis. B.G. and R.P. performed the theoretical calculations and corresponding analysis. D.L. and M.O. grew and reduced the nickelate films. K.L., D.L., M.O. and B.Y.W. conducted materials and structural characterization. B.H.G., L.F.K., B.G. and R.P. wrote the paper. All authors discussed the results and revised the paper.

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Correspondence to Berit H. Goodge or Lena F. Kourkoutis.

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Goodge, B.H., Geisler, B., Lee, K. et al. Resolving the polar interface of infinite-layer nickelate thin films. Nat. Mater. 22, 466–473 (2023). https://doi.org/10.1038/s41563-023-01510-7

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