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Superconductivity at 43 K in an iron-based layered compound LaO1-xFxFeAs

Abstract

The iron- and nickel-based layered compounds LaOFeP (refs 1, 2) and LaONiP (ref. 3) have recently been reported to exhibit low-temperature superconducting phases with transition temperatures Tc of 3 and 5 K, respectively. Furthermore, a large increase in the midpoint Tc of up to 26 K has been realized4 in the isocrystalline compound LaOFeAs on doping of fluoride ions at the O2- sites (LaO1-xFxFeAs). Experimental observations5,6 and theoretical studies7,8,9 suggest that these transitions are related to a magnetic instability, as is the case for most superconductors based on transition metals. In the copper-based high-temperature superconductors, as well as in LaOFeAs, an increase in Tc is often observed as a result of carrier doping in the two-dimensional electronic structure through ion substitution in the surrounding insulating layers, suggesting that the application of external pressure should further increase Tc by enhancing charge transfer between the insulating and conducting layers. The effects of pressure on these iron oxypnictide superconductors may be more prominent than those in the copper-based systems, because the As ion has a greater electronic polarizability, owing to the covalency of the Fe–As chemical bond, and, thus, is more compressible than the divalent O2- ion. Here we report that increasing the pressure causes a steep increase in the onset Tc of F-doped LaOFeAs, to a maximum of 43 K at 4 GPa. With the exception of the copper-based high-Tc superconductors, this is the highest Tc reported to date. The present result, together with the great freedom available in selecting the constituents of isocrystalline materials with the general formula LnOTMPn (Ln, Y or rare-earth metal; TM, transition metal; Pn, group-V, ‘pnicogen’, element), indicates that the layered iron oxypnictides are promising as a new material platform for further exploration of high-temperature superconductivity.

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Figure 1: Schematic crystal structure of LaOFeAs.
Figure 2: Superconducting properties in LaO 0.89 F 0.11 FeAs under high pressure.
Figure 3: Temperature dependence of the electrical resistivity of LaO 0.95 F 0.05 FeAs below 3 GPa, using the piston–cylinder device.

References

  1. Kamihara, Y. et al. Iron-based layered superconductor: LaOFeP. J. Am. Chem. Soc. 128, 10012–10013 (2006)

    CAS  Article  Google Scholar 

  2. Liang, C. Y. et al. Synthesis and structural characterization of LaOFeP superconductors. Supercond. Sci. Technol. 20, 687–690 (2007)

    CAS  ADS  Article  Google Scholar 

  3. Watanabe, T. et al. Nickel-based oxyphosphide superconductor with a layered crystal structure, LaNiOP. Inorg. Chem. 46, 7719–7721 (2007)

    CAS  Article  Google Scholar 

  4. Kamihara, Y., Watanabe, T., Hirano, M. & Hosono, H. Iron-based layered superconductor La[O1-xFx]FeAs (x = 0.05–0.12) with Tc = 26 K. J. Am. Chem. Soc. 130, 3296–3297 (2008)

    CAS  Article  Google Scholar 

  5. Kohama, Y. et al. Ferromagnetic spin fluctuation in LaFeAsO1-xFx . Phys. Rev. Lett. (submitted)

  6. Nakai, Y., Ishida, K., Kamihara, Y., Hirano, M. & Hosono, H. Spin dynamics in iron-based layered superconductor La0. 87Ca0. 13OFeP revealed by 31P and 139La NMR studies. Phys. Rev. Lett. (submitted)

  7. Ishibashi, S., Terakura, K. & Hosono, H. A possible ground state and its electronic structure of a mother material (LaOFeAs) of new superconductors. J. Phys. Soc. Jpn (in the press)

  8. Kuroki, K. et al. Unconventional superconductivity originating from disconnected Fermi surfaces in LaO1-xFxFeAs. Preprint at 〈http://arxiv.org/abs/0803.3325〉 (2008)

  9. Singh, D. J. & Du, M.-H. LaFeAsO1-xFx: A low carrier density superconductor near itinerant magnetism. Preprint at 〈http://arxiv.org/abs/0803.0429〉 (2008)

  10. Takahashi, H. & Mori, N. in Studies of High Temperature Superconductors Vol. 16 (ed. Narlikar, A.) 1–63 (Nova Science, New York, 1996)

    Google Scholar 

  11. Uehara, M. et al. Superconductivity in the spin ladder system Sr0. 4Ca13. 6Cu24O41. 84 . J. Phys. Soc. Jpn. 65, 2764–2767 (1996)

    CAS  ADS  Article  Google Scholar 

  12. Yanagi, H. et al. Itinerant ferromagnetism in layered crystals LaCoOPn(Pn = P, As). Phys. Rev. B (submitted)

  13. Maeno, Y. et al. Superconductivity in a layered perovskite without copper. Nature 372, 532–534 (1994)

    CAS  ADS  Article  Google Scholar 

  14. Ishida, K. et al. Spin-triplet superconductivity in Sr2RuO4 identified by 17O Knight shift. Nature 396, 658–660 (1998)

    CAS  ADS  Article  Google Scholar 

  15. Shimizu, K. et al. Superconductivity in the non-magnetic state of iron under pressure. Nature 412, 316–318 (2001)

    CAS  ADS  Article  Google Scholar 

  16. Saxena, S. S. et al. Superconductivity on the border of itinerant-electron ferromagnetism in UGe2 . Nature 406, 587–592 (2000)

    CAS  ADS  Article  Google Scholar 

  17. Matsumoto, T. Materials for high-pressure apparatus. Rev. High Pressure Sci. Technol. 12, 280–287 (2002)

    CAS  Article  Google Scholar 

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Correspondence to Hiroki Takahashi.

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Takahashi, H., Igawa, K., Arii, K. et al. Superconductivity at 43 K in an iron-based layered compound LaO1-xFxFeAs. Nature 453, 376–378 (2008). https://doi.org/10.1038/nature06972

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