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RETRACTED ARTICLE: Evidence of near-ambient superconductivity in a N-doped lutetium hydride

This article was retracted on 07 November 2023

This article has been updated

Abstract

The absence of electrical resistance exhibited by superconducting materials would have enormous potential for applications if it existed at ambient temperature and pressure conditions. Despite decades of intense research efforts, such a state has yet to be realized1,2. At ambient pressures, cuprates are the material class exhibiting superconductivity to the highest critical superconducting transition temperatures (Tc), up to about 133 K (refs. 3,4,5). Over the past decade, high-pressure ‘chemical precompression’6,7 of hydrogen-dominant alloys has led the search for high-temperature superconductivity, with demonstrated Tc approaching the freezing point of water in binary hydrides at megabar pressures8,9,10,11,12,13. Ternary hydrogen-rich compounds, such as carbonaceous sulfur hydride, offer an even larger chemical space to potentially improve the properties of superconducting hydrides14,15,16,17,18,19,20,21. Here we report evidence of superconductivity on a nitrogen-doped lutetium hydride with a maximum Tc of 294 K at 10 kbar, that is, superconductivity at room temperature and near-ambient pressures. The compound was synthesized under high-pressure high-temperature conditions and then—after full recoverability—its material and superconducting properties were examined along compression pathways. These include temperature-dependent resistance with and without an applied magnetic field, the magnetization (M) versus magnetic field (H) curve, a.c. and d.c. magnetic susceptibility, as well as heat-capacity measurements. X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and theoretical simulations provide some insight into the stoichiometry of the synthesized material. Nevertheless, further experiments and simulations are needed to determine the exact stoichiometry of hydrogen and nitrogen, and their respective atomistic positions, in a greater effort to further understand the superconducting state of the material.

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Fig. 1: Superconductivity in lutetium–nitrogen–hydrogen at near-ambient pressures.
Fig. 2: Temperature-dependent and field-dependent electrical resistance and VI behaviour of the lutetium–nitrogen–hydrogen system.
Fig. 3: Magnetic susceptibility.
Fig. 4: Specific-heat-capacity measurement on the superconducting lutetium–nitrogen–hydrogen system.
Fig. 5: XRD studies of the superconducting lutetium–nitrogen–hydrogen system.

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Data availability

The authors declare that the data supporting the findings of this study are available in the article and its supplementary information files and from the public link https://doi.org/10.5281/zenodo.7374510Source data are provided with this paper.

Change history

  • 24 March 2023

    In the version of this article initially published, the Figure 2 Source data file was an incorrect version and has now been updated in the HTML version of the article.

  • 01 September 2023

    Editor’s Note: Readers are alerted that the reliability of data presented in this manuscript is currently in question. Appropriate editorial action will be taken once this matter is resolved.

  • 07 November 2023

    This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1038/s41586-023-06774-2

References

  1. Onnes, H. K. The resistance of pure mercury at helium temperatures. Commun. Phys. Lab. Univ. Leiden12, 120 (1911).

    Google Scholar 

  2. Ginzburg, V. L. Nobel Lecture: On superconductivity and superfluidity (what I have and have not managed to do) as well as on the “physical minimum” at the beginning of the XXI century. Rev. Mod. Phys.76, 981–998 (2004).

    Article  ADS  CAS  Google Scholar 

  3. Bednorz, J. G. & Müller, K. A. Possible high Tc superconductivity in the Ba–La–Cu–O system. Z. Phys. B Condens. Matter64, 189–193 (1986).

    Article  ADS  CAS  Google Scholar 

  4. 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, 908–910 (1987).

    Article  ADS  CAS  PubMed  Google Scholar 

  5. Schilling, A., Cantoni, M., Guo, J. D. & Ott, H. R. Superconductivity above 130 K in the Hg–Ba–Ca–Cu–O system. Nature363, 56–58 (1993).

    Article  ADS  CAS  Google Scholar 

  6. Carlsson, A. E. & Ashcroft, N. W. Approaches for reducing the insulator-metal transition pressure in hydrogen. Phys. Rev. Lett.50, 1305–1308 (1983).

    Article  ADS  CAS  Google Scholar 

  7. Ashcroft, N. W. Hydrogen dominant metallic alloys: high temperature superconductors? Phys. Rev. Lett.92, 187002 (2004).

    Article  ADS  CAS  PubMed  Google Scholar 

  8. Liu, H., Naumov, I. I., Hoffmann, R., Ashcroft, N. W. & Hemley, R. J. Potential high-Tc superconducting lanthanum and yttrium hydrides at high pressure. Proc. Natl Acad. Sci.114, 6990–6995 (2017).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  9. Peng, F. et al. Hydrogen clathrate structures in rare earth hydrides at high pressures: possible route to room-temperature superconductivity. Phys. Rev. Lett.119, 107001 (2017).

    Article  ADS  PubMed  Google Scholar 

  10. Drozdov, A. P. et al. Superconductivity at 250 K in lanthanum hydride under high pressures. Nature569, 528–531 (2019).

    Article  ADS  CAS  PubMed  Google Scholar 

  11. Somayazulu, M. et al. Evidence for superconductivity above 260 K in lanthanum superhydride at megabar pressures. Phys. Rev. Lett.122, 27001 (2019).

    Article  ADS  CAS  Google Scholar 

  12. Snider, E. et al. Synthesis of yttrium superhydride superconductor with a transition temperature up to 262 K by catalytic hydrogenation at high pressures. Phys. Rev. Lett.126, 117003 (2021).

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Troyan, I. A. et al. Anomalous high‐temperature superconductivity in YH6. Adv. Mater.33, 2006832 (2021).

    Article  CAS  Google Scholar 

  14. Snider, E. et al. Retraction article: Room-temperature superconductivity in a carbonaceous sulfur hydride. Nature586, 373–377 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  15. Snider, E. et al. Retraction note: Room-temperature superconductivity in a carbonaceous sulfur hydride. Nature610, 804 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  16. Smith, G. A. et al. Carbon content drives high temperature superconductivity in a carbonaceous sulfur hydride below 100 GPa. Chem. Commun.58, 9064–9067 (2022).

    Article  CAS  Google Scholar 

  17. Sun, Y., Lv, J., Xie, Y., Liu, H. & Ma, Y. Route to a superconducting phase above room temperature in electron-doped hydride compounds under high pressure. Phys. Rev. Lett.123, 097001 (2019).

    Article  ADS  CAS  PubMed  Google Scholar 

  18. Ge, Y., Zhang, F. & Hemley, R. J. Room-temperature superconductivity in boron- and nitrogen-doped lanthanum superhydride. Phys. Rev. B104, 214505 (2021).

    Article  ADS  CAS  Google Scholar 

  19. Grockowiak, A. D. et al. Hot hydride superconductivity above 550 K. Front. Electron. Mater.2, 837651 (2022).

    Article  Google Scholar 

  20. Zhang, Z. et al. Design principles for high-temperature superconductors with a hydrogen-based alloy backbone at moderate pressure. Phys. Rev. Lett.128, 047001 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  21. Di Cataldo, S., Heil, C., von der Linden, W. & Boeri, L. LaBH8: towards high-Tc low-pressure superconductivity in ternary superhydrides. Phys. Rev. B104, L020511 (2021).

    Article  Google Scholar 

  22. Ashcroft, N. W. Metallic hydrogen: a high-temperature superconductor? Phys. Rev. Lett.21, 1748 (1968).

    Article  ADS  CAS  Google Scholar 

  23. Richardson, C. F. & Ashcroft, N. W. High temperature superconductivity in metallic hydrogen: electron-electron enhancements. Phys. Rev. Lett.78, 118–121 (1997).

    Article  ADS  CAS  Google Scholar 

  24. Dias, R. P. & Silvera, I. F. Observation of the Wigner-Huntington transition to metallic hydrogen. Science355, 715–718 (2017).

    Article  ADS  CAS  PubMed  Google Scholar 

  25. Loubeyre, P., Occelli, F. & Dumas, P. Synchrotron infrared spectroscopic evidence of the probable transition to metal hydrogen. Nature577, 631–635 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  26. Wang, H., Tse, J. S., Tanaka, K., Iitaka, T. & Ma, Y. Superconductive sodalite-like clathrate calcium hydride at high pressures. Proc. Natl Acad. Sci.109, 6463–6466 (2012).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  27. Drozdov, A. P., Eremets, M. I., Troyan, I. A., Ksenofontov, V. & Shylin, S. I. Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system. Nature525, 73–76 (2015).

    Article  ADS  CAS  PubMed  Google Scholar 

  28. Bi, T., Zarifi, N., Terpstra, T. & Zurek, E. in Reference Module in Chemistry, Molecular Sciences and Chemical Engineering (Elsevier, 2019).

  29. Hilleke, K. P. & Zurek, E. Tuning chemical precompression: theoretical design and crystal chemistry of novel hydrides in the quest for warm and light superconductivity at ambient pressures. J. Appl. Phys.131, 070901 (2022).

    Article  ADS  CAS  Google Scholar 

  30. Di Cataldo, S., von der Linden, W. & Boeri, L. First-principles search of hot superconductivity in La-X-H ternary hydrides. npj Comput. Mater.8, 2 (2022).

  31. Di Cataldo, S., Qulaghasi, S., Bachelet, G. B. & Boeri, L. High-Tc superconductivity in doped boron-carbon clathrates. Phys. Rev. B105, 064516 (2022).

    Article  ADS  Google Scholar 

  32. Ye, X., Zarifi, N., Zurek, E., Hoffmann, R. & Ashcroft, N. W. High hydrides of scandium under pressure: potential superconductors. J. Phys. Chem. C122, 6298–6309 (2018).

    Article  CAS  Google Scholar 

  33. Shannon, R. D. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. A32, 751–767 (1976).

    Article  ADS  Google Scholar 

  34. Rumble, J. R. (ed.) CRC Handbook of Chemistry and Physics 102nd edn (CRC Press/Taylor & Francis, 2021).

  35. Greenwood, N. N. & Earnshaw, A. (eds) Chemistry of the Elements 2nd edn (Butterworth-Heinemann, 1997).

  36. Zhou, D. et al. Superconducting praseodymium superhydrides. Sci. Adv.6, 6849–6877 (2020).

    Article  ADS  Google Scholar 

  37. Zhou, D. et al. High-pressure synthesis of magnetic neodymium polyhydrides. J. Am. Chem. Soc.142, 2803–2811 (2020).

    Article  CAS  PubMed  Google Scholar 

  38. Semenok, D. V. et al. Effect of magnetic impurities on superconductivity in LaH10. Adv. Mater.34, 2204038 (2022).

  39. Sun, W., Kuang, X., Keen, H. D. J., Lu, C. & Hermann, A. Second group of high-pressure high-temperature lanthanide polyhydride superconductors. Phys. Rev. B102, 144524 (2020).

    Article  ADS  CAS  Google Scholar 

  40. Jaroń, T. et al. Synthesis, structure, and electric conductivity of higher hydrides of ytterbium at high pressure. Inorg. Chem.61, 8694–8702 (2022).

    Article  PubMed  PubMed Central  Google Scholar 

  41. Song, H. et al. High Tc superconductivity in heavy rare earth hydrides. Chin. Phys. Lett.38, 107401 (2021).

    Article  ADS  Google Scholar 

  42. Cornelius, A. L., Lawler, K. V. & Salamat, A. Understanding hydrogen rich superconductors: importance of effective mass and dirty limit. Preprint at https://doi.org/10.48550/arxiv.2202.04254 (2022).

  43. Dasenbrock-Gammon, N., McBride, R., Yoo, G., Dissanayake, S. & Dias, R. Second harmonic AC calorimetry technique within a diamond anvil cell. Rev. Sci. Instrum.93, 093901 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  44. Klesnar, H. P. & Rogl, P. Phase relations in the ternary systems rare-earth metal (RE)-boron-nitrogen, where RE = Tb, Dy, Ho, Er, Tm, Lu, Sc and Y. High Temp. High Press.22, 453–457 (1990).

    CAS  Google Scholar 

  45. Pebler, A. & Wallace, W. E. Crystal structures of some lanthanide hydrides. J. Phys. Chem.66, 148–151 (1962).

    Article  CAS  Google Scholar 

  46. Bonnet, J. E. & Daou, J. N. Rare‐earth dihydride compounds: lattice thermal expansion and investigation of the thermal dissociation. J. Appl. Phys.48, 964–968 (1977).

    Article  ADS  CAS  Google Scholar 

  47. Weaver, J. H., Rosei, R. & Peterson, D. T. Electronic structure of metal hydrides. I. Optical studies of ScH2, YH2, and LuH2. Phys. Rev. B19, 4855–4866 (1979).

    Article  ADS  CAS  Google Scholar 

  48. Peterman, D. J., Harmon, B. N., Marchiando, J. & Weaver, J. H. Electronic structure of metal hydrides. II. Band theory of ScH2 and YH2. Phys. Rev. B19, 4867–4875 (1979).

    Article  ADS  CAS  Google Scholar 

  49. Daou, J. N., Vajda, P., Burger, J. P. & Shaltiel, D. Percolating electrical conductivity in two phased LuH2+x compounds. Europhys. Lett.6, 647–651 (1988).

    Article  ADS  CAS  Google Scholar 

  50. Daou, J. N., Vajda, P., Burger, J. P. & Shaltiel, D. Percolating electrical conductivity in two phased LuH2+x compounds. Europhys. Lett.8, 587 (1989).

    Article  ADS  CAS  Google Scholar 

  51. Mansmann, M. & Wallace, W. E. The structure of HoD3. J. Phys.25, 454–459 (1964).

    Article  CAS  Google Scholar 

  52. Palasyuk, T. & Tkacz, M. Pressure-induced structural phase transition in rare-earth trihydrides. Part I. (GdH3, HoH3, LuH3). Solid State Commun.133, 481–486 (2005).

    Article  ADS  CAS  Google Scholar 

  53. Daou, J. N., Lucasson, A., Vajda, P. & Burger, J. P. Observation of the optical and acoustic electron-phonon coupling in Sc, Y and Lu dihydrides and dideuterides by electrical resistivity. J. Phys. F Metal Phys.14, 2983–2993 (1984).

    Article  ADS  CAS  Google Scholar 

  54. Kataoka, R. et al. The origin of the highly crystallized face-centered cubic YH3 high-pressure phase when quenched to ambient condition. Mater. Today Commun.31, 103265 (2022).

    Article  CAS  Google Scholar 

  55. Renaudin, G., Fischer, P. & Yvon, K. Neodymium trihydride, NdH3, with tysonite type structure. J. Alloys Compd.313, L10–L14 (2000).

    Article  CAS  Google Scholar 

  56. Villa-Cortés, S. & De la Peña-Seaman, O. Effect of van Hove singularity on the isotope effect and critical temperature of H3S hydride superconductor as a function of pressure. J. Phys. Chem. Solids161, 110451 (2022).

    Article  Google Scholar 

  57. Liang, X. et al. Prediction of high-Tc superconductivity in ternary lanthanum borohydrides. Phys. Rev. B104, 134501 (2021).

    Article  ADS  CAS  Google Scholar 

  58. Belli, F. & Errea, I. Impact of ionic quantum fluctuations on the thermodynamic stability and superconductivity of. Phys. Rev. B106, 134509 (2022).

    Article  ADS  CAS  Google Scholar 

  59. Errea, I. Superconducting hydrides on a quantum landscape. J. Phys. Condens. Matter34, 231501 (2022).

    Article  ADS  CAS  Google Scholar 

  60. Shen, G. et al. Toward an international practical pressure scale: a proposal for an IPPS ruby gauge (IPPS-Ruby2020). High Press. Res.40, 299–314 (2020).

    Article  ADS  Google Scholar 

  61. Datchi, F. et al. Optical pressure sensors for high-pressure–high-temperature studies in a diamond anvil cell. High Press. Res.27, 447–463 (2007).

    Article  ADS  CAS  Google Scholar 

  62. Dias, R. P., Yoo, C.-S., Kim, M. & Tse, J. S. Insulator-metal transition of highly compressed carbon disulfide. Phys. Rev. B84, 144104 (2011).

    Article  ADS  Google Scholar 

  63. Li, Y.-S., Borth, R., Hicks, C. W., Mackenzie, A. P. & Nicklas, M. Heat-capacity measurements under uniaxial pressure using a piezo-driven device. Rev. Sci. Instrum.91, 103903 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  64. Kraftmakher, Y. Modulation Calorimetry. Theory and Applications (Springer, 2004).

  65. Debessai, M., Hamlin, J. J. & Schilling, J. S. Comparison of the pressure dependences of Tc in the trivalent d-electron superconductors Sc, Y, La, and Lu up to megabar pressures. Phys. Rev. B78, 064519 (2008).

    Article  ADS  Google Scholar 

  66. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett.77, 3865–3868 (1996).

    Article  ADS  CAS  PubMed  Google Scholar 

  67. Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter21, 395502 (2009).

    Article  PubMed  Google Scholar 

  68. Giannozzi, P. et al. Advanced capabilities for materials modelling with Quantum ESPRESSO. J. Phys. Condens. Matter29, 465901 (2017).

    Article  CAS  PubMed  Google Scholar 

  69. van Setten, M. J. et al. The PseudoDojo: training and grading a 85 element optimized norm-conserving pseudopotential table. Comput. Phys. Commun.226, 39–54 (2018).

    Article  ADS  Google Scholar 

  70. Dudarev, S. L., Botton, G. A., Savrasov, S. Y., Humphreys, C. J. & Sutton, A. P. Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA+U study. Phys. Rev. B57, 1505–1509 (1998).

    Article  ADS  CAS  Google Scholar 

  71. Cococcioni, M. & de Gironcoli, S. Linear response approach to the calculation of the effective interaction parameters in the LDA+U method. Phys. Rev. B71, 035105 (2005).

    Article  ADS  Google Scholar 

  72. Topsakal, M. & Wentzcovitch, R. M. Accurate projected augmented wave (PAW) datasets for rare-earth elements (RE = La–Lu). Comput. Mater. Sci.95, 263–270 (2014).

    Article  CAS  Google Scholar 

  73. Dal Corso, A. Pseudopotentials periodic table: from H to Pu. Comput. Mater. Sci.95, 337–350 (2014).

    Article  CAS  Google Scholar 

  74. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B50, 17953–17979 (1994).

    Article  ADS  Google Scholar 

  75. Peterman, D. J., Weaver, J. H. & Peterson, D. T. Electronic structure of metal hydrides. V. x-dependent properties of LaHx (1.9 < ~x < 2.9) and NdHx (2.01 < ~x < ~2.27). Phys. Rev. B23, 3903–3913 (1981).

    Article  ADS  CAS  Google Scholar 

  76. Knappe, P., Müller, H. & Mayer, H. W. Tetragonal rare earth hydrides REH(D)≈2.33 (RE = La, Ce, Pr, Nd, Sm) and a neutron diffraction study of NdD2.36. J. Less Common Metals95, 323–333 (1983).

    Article  CAS  Google Scholar 

  77. Errea, I. et al. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system. Nature532, 81–84 (2016).

    Article  ADS  CAS  PubMed  Google Scholar 

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Acknowledgements

We thank B. Brennessel from the Department of Chemistry at the University of Rochester for providing the technical assistance during the XRD and elemental analysis. We thank M. Debessai for his assistance on the coil setup for the magnetic-susceptibility measurements. Also, we thank I. Silvera and I. Hogarth for the useful scientific discussions and R. C. Heist and L. Koelbl for reading through the manuscript and providing valuable suggestions. Preparation of diamond surfaces and EDX measurements were performed in part at the University of Rochester Integrated Nanosystems Center. Computational resources were provided by the Center for Integrated Research Computing at the University of Rochester. This research was supported by NSF grant no. DMR-2046796, Unearthly Materials Inc. and US Department of Energy, Office of Science, Fusion Energy Sciences under award number DE-SC0020340.

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Authors and Affiliations

Authors

Contributions

N.D.-G., E.S., R.M. and H.P. contributed equally to this work as co-first authors. E.S., D.D., N.D.-G., R.M., H.P. and R.P.D. contributed to performing the electrical-conductivity measurements. N.D.-G., N.K.-S., S.M., S.E.D. and R.P.D. contributed to performing a.c. magnetic-susceptibility measurements and analysed the data. N.D.-G., R.M. and R.P.D. contributed to performing heat-capacity measurements and the analysis. E.S., N.D.-G., R.M., D.D., H.P. and S.E.D. contributed to performing elemental analysis, EDX studies and XRD measurements. H.P., R.M., S.E.D. and R.P.D. contributed to performing Raman studies and H.P. and R.P.D. analysed the data. S.E.D. and A.S. performed structure analysis. H.P., S.E.D. and R.P.D. performed the magnetization measurements using a PPMS and R.P.D. analysed the data. K.V.L. and A.S. performed the simulations and analysed the data and chemistry protocol. N.D.-G., K.V.L., A.S., S.E.D. and R.P.D. wrote the paper. All authors discussed the results and commented on the manuscript. R.P.D. conceived the project and oversaw the entire project.

Corresponding author

Correspondence to Ranga P. Dias.

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Competing interests

The University of Rochester (U of R) has patents pending related to the discoveries of R.P.D. in the field of superconductivity. R.P.D. is a cofounder and chairman of the board of Unearthly Materials Inc. (UM), a Delaware corporation. UM has licensing agreements with U of R related to the patents, proprietary interests and commercialization rights related to the scientific discoveries of R.P.D. UM, U of R and R.P.D. are subject to non-disclosure and confidentiality agreements. A.S. is a cofounder, president, chief executive officer and board member of UM.

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This article has been retracted. Please see the retraction notice for more detail:https://doi.org/10.1038/s41586-023-06774-2

Extended data figures and tables

Extended Data Fig. 1 Raman spectra.

a, The spectral deconvolution of Raman spectra of compound A on compression. b, The Raman shift versus pressure of compound A at high pressures, indicating the three distinct phases. c, The spectral deconvolution of Raman spectra of compound B on compression.

Source data

Extended Data Fig. 2 The heat-capacity setup.

Top, schematic rendering of the new a.c calorimetry technique (not to scale). The sample is surrounded by a NaCl insert with a heater and thermocouple making contact with the sample. a, View of the preparation as seen from the side showing the thermocouple making contact with the sample inside the DAC. b, View of the preparation as seen from the top of the sample area showing the configuration of heater, thermocouple and Pt leads. Bottom left, heat-capacity setup before loading sample. The thermocouple consists of a shorted alumel/chromel pair. The heater pair consists of a shorted metal, nichrome, Ti or Pt. When driven at frequency f, the sample temperature modulates at frequency 2 × ƒ, which manifests as a voltage on the thermocouple pair that can be measured by a lock-in amplifier. Bottom right, after the sample is loaded, in contact with both the heater and the thermocouple, a small piece of NaCl is placed on top to thermally insulate it from the diamond.

Extended Data Fig. 3 Frequency response.

Frequency and current sweeps measured on a heat-capacity setup before running the experiment. The frequency sweep shows the characteristic plateau and the current sweep demonstrates quadratic dependence, as expected from ohmic heating.

Extended Data Fig. 4 Heat capacity.

Specific heat capacity of MgB2 as a function of temperature at 15 kbar and 127 Hz. The superconducting signature is clearly observed at 32 K. Inset, recorded lock-in voltages during the frequency sweeps at 60 K.

Source data

Extended Data Fig. 5 a.c. susceptibility data before background subtraction.

Voltage in volts versus temperature plots at different pressures before the background subtraction. Cubic or quadratic polynomial background was used for background subtraction for susceptibility data. This figure shows fittings with cubic or quadratic polynomials indicated by the red lines. For a.c. susceptibility data, the background subtraction was done mainly for visualization purposes.

Source data

Extended Data Fig. 6 Further a.c. susceptibility measurements.

a, The a.c. susceptibility in nanovolts versus temperature for a larger sample of the N-doped Lu hydride system at select pressures from run 2, showing large diamagnetic signal of the superconducting transition owing to the large volume of the sample. The superconducting transition shifts rapidly under pressure to lower temperatures. a.c. susceptibility measurements taken over broader temperature ranges for N-doped Lu hydride at 4 kbar (b), 6 kbar (c) and 8 kbar (d). The red line in bd is the quadratic fit for the background and the insets show the signals with the background subtracted. e, a.c. susceptibility measurements of MgB2 as a function of temperature using exact same coil set up as the test sample.

Source data

Extended Data Fig. 7 EDX measurements.

For EDX measurements, samples were prepared by mounting on an aluminium pin mount with double-sided carbon tape. The samples were then imaged using a Zeiss Auriga scanning electron microscope. Regions of interest were chosen by comparing the scanning electron microscopy image to a white-light image taken beforehand. EDX measurements were performed in the Zeiss Auriga scanning electron microscope with a driving energy of 15 kV and collected and analysed using an EDAX detector with the EDAX APEX software. Carbon and aluminium peaks seen in the EDX spectra originating from the carbon tape and aluminium mount required to place the samples into the scanning electron microscope vacuum chamber. EDX measurements provide further evidence for the presence of nitrogen in our samples.

Source data

Extended Data Fig. 8 Phonon bands of stoichiometric Lu hydrides.

The calculated phonon band structures of 0 kbar LuH2 in the fluorite structure (a), \(Fm\bar{3}m\) LuH3 (b), LuH in the RS structure (c) and LuH in the ZB structure (d). e, The calculated phonon band structures of 0 kbar LuH2 in the fluorite structure using a triclinic representation of the lattice vectors with x parallel to a and z parallel to c*, as opposed to the more highly symmetric lattice vectors for a primitive cell of a fcc cell; in this representation, the structure is represented with D3d point-group symmetry as opposed to Oh point-group symmetry as in a. f, The calculated phonon band structures of 0 kbar LuH3 using the same triclinic representation of the lattice vectors and point-group symmetry as in e.

Extended Data Fig. 9 Rietveld refinement of site occupancies.

a, Rietveld refinement of the X-ray powder diffraction data collected at 295 K with Cu Kα radiation with refining the occupancy of the tetrahedral interstitial site with N for nitrogen-doped lutetium hydride. b, Simulation of the XRD pattern with Cu Kα wavelength for LuH3 (red), LuH3 with a N replacing a single H in an octahedral site (blue) and a tetrahedral site (green). Rietveld refinement of the X-ray powder diffraction data of ground powder sample was performed with an attempt to investigate the possible N substitution in nitrogen-doped lutetium hydride. We note here that XRD is mostly dominated by heavy Lu atoms.

Extended Data Fig. 10 Projected density of states.

The atom and angular momentum projected partial density of states of LuH2 in the fluorite structure (a); \(Fm\bar{3}m\) LuH3 (b); the cubic cell of \(Fm\bar{3}m\) LuH3 with a N substituted for a H in an octahedral (c) and tetrahedral (d) interstice; and a 2 × 2 × 2 supercell of the rhombohedral primitive cell of \(Fm\bar{3}m\) LuH3 with a N substituted for a H in an octahedral (e) and tetrahedral (f) interstice. In the legends, Oct- means hydrogens in the octahedral interstices and Tet- means hydrogens in the tetrahedral interstices. Each channel is summed over all similar atoms in the unit cell and the plots are scaled to represent a maximum value of 2.5 states eV−1 per formula unit.

Extended Data Fig. 11 Distorted structures predicted by DFT.

a, The distortions to the octahedral hydrogens observed by substituting a N atom for a tetrahedral atom in a single unit cell of \(Fm\bar{3}m\) LuH3. b, The Pmnm LuH3 structure found by perturbing the cubic \(Fm\bar{3}m\) unit cell of LuH3, which suggests possible light-atom positions in phase III. c, The lattice distortions from substituting a N into a tetrahedral interstice in a 2 × 2 × 2 supercell of the rhombohedral primitive of LuH3. d, The lattice distortions from substituting a N into an octahedral interstice in a 2 × 2 × 2 supercell of the rhombohedral primitive of LuH3. The lutetium atoms are green, the nitrogen atoms are lavender and the hydrogen atoms in octahedral interstitial sites are white and those in tetrahedral interstitial sites are pink. In b, there is no distinction made between the hydrogen atom sites, so they are all white.

Extended Data Fig. 12 Superconducting transition widths.

For comparison, the superconducting transition obtained from electrical measurements and a.c. susceptibility measurement at a similar pressure (16 kbar) is shown by red and blue, respectively. The transition width of the resistance drop is 1.3 K and 1.6 K for the a.c. magnetic susceptibility measurement.

Source data

Extended Data Fig. 13 Low-temperature electrical-resistance behaviour of N-doped Lu–H systems.

a, The resistance measured on both warming and cooling at about 10 kbar. b, Temperature-dependent electrical resistance of phases I and III, showing the non-superconducting state. c, Four-probe electrical-resistance measurements of different Lu–H–N samples, which consistently shows highly metallic behaviour with decreasing temperature.

Extended Data Fig. 14 Magnetic-susceptibility background and smoothing.

ac, The ZFC and FC magnetization versus temperature at 8 kbar used to construct Fig. 3a, along with a linear fit to the data at temperatures above the transition temperature, which was used for the background subtraction. d, The ZFC and FC curves with the linear backgrounds shown in b and c subtracted out, as well as with a ten-point adjacent-average smoothing applied. e, The measured cell background at 60 Oe for the HMD cell used for the d.c. measurements.

Source data

Extended Data Fig. 15 Electrical-resistance behaviour under magnetic field.

Low-temperature electrical-resistance behaviour under magnetic fields of H = 0 T, 1 T and 3 T (increasing from right to left) at 15 kbar. In this study, the superconductivity of nitrogen-doped lutetium hydride is suppressed by the application of a 3-T external magnetic field, reducing Tc by about 5 K at 15 kbar, further confirming a superconducting transition. The temperature dependence of the resistance of a simple metal is written as: R(T) = Ro + aT2 + bT5. We fit the data below T < 220 K for each field, at which the resistance goes to the minimum value, to that function and subtracted it out. Inset top, the superconducting transition width, ΔTc, at 15 kbar slightly increases under external magnetic fields. The ΔTc has a good linear relationship with the applied magnetic field, as expected from the percolation model. The superconducting transition width is defined here as ΔTc = T90% − T10%, in which T90% and T10% are the temperatures corresponding to 90% and 10% of the resistance at 292 K, respectively. Fitting to the linear relation of ΔTc = ΔTc(0) + kHc2, in which ΔTc(0) is the width at zero external field and k is a constant, provides the values ΔTc(0) = 36.3 K and k = 0.07 KT−1. The large transition width at zero field indicates sample inhomogeneities, which is typical for high-pressure experiments. Inset bottom, the temperature dependence of the upper critical field, \({H}_{{\rm{c}}}\left(T\right)={H}_{{\rm{c}}}\left(0\right)\left[1-{\left(\frac{T}{{T}_{{\rm{c}}}}\right)}^{2}\right]\), can be expressed using GL theory or the conventional Werthamer–Helfand–Hohenberg model. The GL model in the limit of zero temperature yields Hc2(0) ≈ 88 T. From the Werthamer–Helfand–Hohenberg model in the dirty limit, Hc2(0) can be extrapolated from the slope of the HT curve as \({H}_{{\rm{c2}}}\left(0\right)=0.693{\left|\frac{{{\rm{d}}H}_{{\rm{c}}2}}{{\rm{d}}T}\right|}_{T={T}_{{\rm{c}}}}{T}_{{\rm{c}}}\), which yields roughly 122 T.

Source data

Extended Data Fig. 16 Phonon bands of pressurized stoichiometric Lu hydrides.

The calculated phonon band structures of LuH2 in the fluorite structure (left) and LuH in the ZB structure (right) at 0 kbar (top row), 10 kbar (second row), 30 kbar (third row) and 50 kbar (bottom row). The electronic smearing width is 0.005 Ry and the lattice vectors are the highly symmetric ones for a fcc cell. Negligible change in the computed electron–phonon couplings or logarithmic frequency is seen for LuH2 on pressurization.

Supplementary information

Supplementary Video

Notable visual transformation of N-doped lutetium hydride. The high-pressure lutetium–nitrogen–hydrogen system is accompanied by a marked visual transformation over just a few kbar of pressure. The recovered sample is initially in a non-superconducting metallic phase with a lustrous bluish colour, denoted as phase I. Compression to 3 kbar drives the progression of the system into phase II, leading to the superconducting regime, and this transformation is associated with a sudden change in colour from blue to pink. Compression above around 32 kbar drives the sample through another phase transition into phase III. Phase III is a non-superconducting metallic state that is once again distinct in colour, being bright red in appearance.

Theory Plotting Data (ED8)

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Theory Plotting Data (ED11)

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Dasenbrock-Gammon, N., Snider, E., McBride, R. et al. RETRACTED ARTICLE: Evidence of near-ambient superconductivity in a N-doped lutetium hydride. Nature 615, 244–250 (2023). https://doi.org/10.1038/s41586-023-05742-0

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