Article | Published:

Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe

Nature Materials volume 14, pages 325329 (2015) | Download Citation


Iron selenide superconductors exhibit a number of unique characteristics that are helpful for understanding the mechanism of superconductivity in high-Tc iron-based superconductors more generally. However, in the case of AxFe2Se2 (A = K, Rb, Cs), the presence of an intergrown antiferromagnetic insulating phase makes the study of the underlying physics problematic. Moreover, FeSe-based systems intercalated with alkali metal ions, NH3 molecules or organic molecules are extremely sensitive to air, which prevents the further investigation of their physical properties. It is therefore desirable to find a stable and easily accessible FeSe-based superconductor to study its physical properties in detail. Here, we report the synthesis of an air-stable material, (Li0.8Fe0.2)OHFeSe, which remains superconducting at temperatures up to ~40 K, by means of a novel hydrothermal method. The crystal structure is unambiguously determined by a combination of X-ray and neutron powder diffraction and nuclear magnetic resonance. Moreover, antiferromagnetic order is shown to coexist with superconductivity. This synthetic route opens a path for exploring superconductivity in other related systems, and confirms the appeal of iron selenides as a platform for understanding superconductivity in iron pnictides more broadly.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. Superconductivity in the PbO-type structure α-FeSe. Proc. Natl Acad. Sci. USA 105, 14262–14264 (2008).

  2. 2.

    et al. Extreme sensitivity of superconductivity to stoichiometry in Fe1+δSe. Phys. Rev. B 79, 014522 (2009).

  3. 3.

    , , & 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).

  4. 4.

    et al. Superconductivity at 43 K in SmFeAsO1−xFx. Nature 453, 761–762 (2008).

  5. 5.

    , & Superconductivity at 38 K in the iron arsenide Ba1−xKxFe2As2. Phys. Rev. Lett. 101, 107006 (2008).

  6. 6.

    et al. Superconducting Fe-based compounds (A1−xSrx)Fe2As2 with A = K and Cs with transition temperature up to 37 K. Phys. Rev. Lett. 101, 107007 (2008).

  7. 7.

    et al. Pressure evolution of the low-temperature crystal structure and bonding of the superconductor FeSe (TC = 37 K). Phys. Rev. B 80, 064506 (2009).

  8. 8.

    et al. Electronic and magnetic phase diagram of β-Fe1.01Se with superconductivity at 36.7 K under pressure. Nature Mater. 8, 630–633 (2009).

  9. 9.

    et al. Interface-induced high-temperature superconductivity in single unit-cell FeSe films on SrTiO3. Chin. Phys. Lett. 29, 037402 (2012).

  10. 10.

    et al. Electronic origin of high-temperature superconductivity in single-layer FeSe superconductor. Nature Commun. 3, 931 (2012).

  11. 11.

    et al. Phase diagram and electronic indication of high-temperature superconductivity at 65 K in single-layer FeSe films. Nature Mater. 12, 605–610 (2013).

  12. 12.

    et al. Interface-induced superconductivity and strain-dependent spin density waves in FeSe/SrTiO3 thin films. Nature Mater. 12, 634–640 (2013).

  13. 13.

    et al. Nodeless superconducting gap in AxFe2Se2 (A = K, Cs) revealed by angle-resolved photoemission spectroscopy. Nature Mater. 10, 273–277 (2011).

  14. 14.

    et al. Absence of a holelike Fermi surface for the iron-based K0.8Fe1.7Se2 superconductor revealed by angle-resolved photoemission spectroscopy. Phys. Rev. Lett. 106, 187001 (2011).

  15. 15.

    et al. Superconductivity in the iron selenide KxFe2Se2(0 ≤ x ≤ 1.0). Phys. Rev. B 82, 180520(R) (2010).

  16. 16.

    et al. Superconductivity at 32 K in single-crystalline RbxFe2−ySe2. Phys. Rev. B 83, 060512(R) (2011).

  17. 17.

    et al. Synthesis and crystal growth of Cs0.8(FeSe0.98)2: A new iron-based superconductor with TC = 27 K. J. Phys. Condens. Matter 23, 052203 (2011).

  18. 18.

    et al. Observation of superconductivity at 30 K ~ 46 K in AxFe2Se2(A = Li, Na, Ba, Sr, Ca, Yb, and Eu). Sci. Rep. 2, 426 (2012).

  19. 19.

    et al. Re-emerging superconductivity at 48 kelvin in iron chalcogenides. Nature 483, 67–69 (2012).

  20. 20.

    et al. Enhancement of the superconducting transition temperature of FeSe by intercalation of a molecular spacer layer. Nature Mater. 12, 15–19 (2013).

  21. 21.

    et al. Synthesis of a new alkali metal–organic solvent intercalated iron selenide superconductor with Tc ≈ 45 K. J. Phys. Condens. Matter 24, 382202 (2012).

  22. 22.

    et al. Phase separation and magnetic order in K-doped iron selenide superconductor. Nature Phys. 8, 126–130 (2012).

  23. 23.

    et al. A novel large moment antiferromagnetic order in K0.8Fe1.6Se2 superconductor. Chin. Phys. Lett. 28, 086104 (2011).

  24. 24.

    et al. Structural phase separation in K0.8Fe1.6+xSe2 superconductors. J. Phys. Chem. C 116, 17847 (2012).

  25. 25.

    et al. Superconductivity in LiFeO2Fe2Se2with anti-PbO-type spacer layers. Phys. Rev. B 89, 020507(R) (2013).

  26. 26.

    et al. Effects of cobalt doping and phase diagrams of LFe1−xCoxAsO (L = La and Sm). Phys. Rev. B 79, 054521 (2009).

  27. 27.

    et al. The pseudogap behavior in the stoichiometric FeSe superconductor (Tc ~ 9.4 K). J. Korean Phys. Soc. 59, 312 (2011).

  28. 28.

    et al. Electronic and magnetic phase diagram in KxFe2−ySe2 superconductors. Sci. Rep. 2, 212 (2011).

Download references


We would like to thank Z. Sun for discussions and Z. Qi for his help on infrared reflectance spectroscopy measurements. This work is supported by the National Natural Science Foundation of China (NSFC), the ‘Strategic Priority Research Program (B)’ of the Chinese Academy of Sciences, and the National Basic Research Program of China (973 Program). (Certain commercial suppliers are identified in this paper to foster understanding. Such identification does not imply recommendation or endorsement by the NIST).

Author information


  1. Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China

    • X. F. Lu
    • , N. Z. Wang
    • , Y. P. Wu
    • , D. Zhao
    • , X. Z. Zeng
    • , X. G. Luo
    • , T. Wu
    •  & X. H. Chen
  2. Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026, China

    • X. F. Lu
    • , N. Z. Wang
    • , Y. P. Wu
    • , D. Zhao
    • , X. Z. Zeng
    • , X. G. Luo
    • , T. Wu
    •  & X. H. Chen
  3. National Institute of Standards and Technology, Center for Neutron Research, 100 Bureau Dr., Gaithersburg Maryland 20878, USA

    • H. Wu
    •  & Q. Z. Huang
  4. Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA

    • H. Wu
  5. Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China

    • X. G. Luo
    • , T. Wu
    •  & X. H. Chen
  6. Department of Physics, Renmin University of China, Beijing 100872, China

    • W. Bao
  7. CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China

    • G. H. Zhang
    •  & F. Q. Huang
  8. Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China

    • G. H. Zhang
    •  & F. Q. Huang


  1. Search for X. F. Lu in:

  2. Search for N. Z. Wang in:

  3. Search for H. Wu in:

  4. Search for Y. P. Wu in:

  5. Search for D. Zhao in:

  6. Search for X. Z. Zeng in:

  7. Search for X. G. Luo in:

  8. Search for T. Wu in:

  9. Search for W. Bao in:

  10. Search for G. H. Zhang in:

  11. Search for F. Q. Huang in:

  12. Search for Q. Z. Huang in:

  13. Search for X. H. Chen in:


X.F.L. and N.Z.W. contributed equally to this work. X.F.L. and N.Z.W. performed sample synthesis, composition determination, susceptibility, specific heat, X-ray diffraction and thermoelectric power measurements with assistance from X.Z.Z. and X.G.L., Q.Z.H., H.W. and W.B. performed NPD experiments and carried out the structure analysis. Y.P.W., D.Z. and T.W. performed NMR experiments and analysed data. G.H.Z. and F.Q.H. carried out the refinement on XRD. X.F.L., N.Z.W., Q.Z.H., T.W. and X.H.C. analysed the data and wrote the paper. X.H.C. conceived and coordinated the project, and is responsible for the infrastructure and project direction. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to X. H. Chen.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

About this article

Publication history





Further reading