Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Multiferroicity in an organic charge-transfer salt that is suggestive of electric-dipole-driven magnetism

Nature Materials volume 11, pages 755–758 (2012)Cite this article

Subjects

Abstract

Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view1,2. A prominent mechanism of multiferroicity is the spin-driven ferroelectricity, often found in frustrated antiferromagnets with helical spin order1,3,4,5. There, as for conventional ferroelectrics, the electrical dipoles arise from an off-centre displacement of ions. However, recently a different mechanism, namely purely electronic ferroelectricity, where charge order breaks inversion symmetry, has attracted considerable interest6. Here we provide evidence for ferroelectricity, accompanied by antiferromagnetic spin order, in a two-dimensional organic charge-transfer salt, thus representing a new class of multiferroics. We propose a charge-order-driven mechanism leading to electronic ferroelectricity in this material. Quite unexpectedly for electronic ferroelectrics, dipolar and spin order arise nearly simultaneously. This can be ascribed to the loss of spin frustration induced by the ferroelectric ordering. Hence, here the spin order is driven by the ferroelectricity, in marked contrast to the spin-driven ferroelectricity in helical magnets.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Temperature dependence of conductivity of κ-(ET)2Cu[N(CN)2]Cl.
Figure 2: Temperature dependence of the dielectric constant.
Figure 3: Electric polarization switching.
Figure 4: Temperature-dependence of the dielectric constant.

Similar content being viewed by others

References

  1. Fiebig, M. Revival of the magnetoelectric effect. J. Phys. D 38, R123-R152 (2005).

    Article  Google Scholar 

  2. Cheong, S-W. & Mostovoy, M. Multiferroics: A magnetic twist for ferroelectricity. Nature Mater. 6, 13–20 (2007).

    Article  CAS  Google Scholar 

  3. Sergienko, I. A. & Dagotto, E. Role of the Dzyaloshinskii–Moriya interaction in multiferroic perovskites. Phys. Rev. B 73, 094434 (2006).

    Article  Google Scholar 

  4. Katsura, H., Nagaosa, N. & Balatsky, A. V. Spin current and magnetoelectric effect in noncollinear magnets. Phys. Rev. Lett. 95, 057205 (2005).

    Article  Google Scholar 

  5. Mostovoy, M. Ferroelectricity in spiral magnets. Phys. Rev. Lett. 96, 067601 (2006).

    Article  Google Scholar 

  6. Van den Brink, J. & Khomskii, D. I. Multiferroicity due to charge ordering. J. Phys. Condens. Matter 20, 434217 (2008).

    Article  Google Scholar 

  7. Kanoda, K. in The Physics of Organic Superconductors and Conductors (ed. Lebed, A.) Ch. 22, 623–642 (Springer, 2008).

    Book  Google Scholar 

  8. Toyota, N., Lang, M. & Müller, J. Low-Dimensional Molecular Metals (Springer, 2007).

    Book  Google Scholar 

  9. Abdel-Jawad, M. et al. Anomalous dielectric response in the dimer Mott insulator κ-(BEDT-TTF)2Cu2(CN)3 . Phys. Rev. B 82, 125119 (2010).

    Article  Google Scholar 

  10. Hotta, C. Quantum electric dipoles in spin-liquid dimer Mott insulator κ-(ET)2Cu2(CN)3 . Phys. Rev. B 82, (R)241104 (2010).

    Article  Google Scholar 

  11. Li, H., Clay, R. T. & Mazumdar, S. The paired-electron crystal in the two-dimensional frustrated quarter-filled band. J. Phys. Condens. Matter 22, 272201 (2010).

    Article  CAS  Google Scholar 

  12. Miyagawa, K., Kawamoto, A., Nakazawa, Y. & Kanoda, K. Antiferromagnetic ordering and spin structure in the organic conductor, κ-(BEDT−TTF)2Cu[N(CN)2]Cl. Phys. Rev. Lett. 75, 1174–1177 (1995).

    Article  CAS  Google Scholar 

  13. Smith, D. F. et al. Dzialoshinskii-Moriya interaction in the organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl. Phys. Rev. B 68, 024512 (2003).

    Article  Google Scholar 

  14. Wang, H. H. et al. New κ-phase materials, κ-(ET)2Cu[N(CN)2]X, X = Cl, Br and I—The synthesis, structure and superconductivity above 11 K in the Cl (Tc = 12.8 K, 0.3 kbar) and Br (Tc = 11.6 K) salts. Synth. Met. 42, 1983–1990 (1991).

    Article  CAS  Google Scholar 

  15. Williams, J. M. et al. From semiconductor-semiconductor transition (42 K) to the highest- T c organic superconductor, κ-(ET)2Cu[N(CN)2]Cl (Tc = 12.5K). Inorg. Chem. 29, 3272–3274 (1990).

    Article  CAS  Google Scholar 

  16. Dressel, M. et al. Studies of the microwave resistivity of κ-(BEDT−TTF)2Cu[N(CN)2]Cl. Synth. Met. 70, 927–928 (1995).

    Article  CAS  Google Scholar 

  17. Lines, M. E. & Glass, A. M. Principles and Application of Ferroelectrics and Related Materials (Clarendon, 1977).

    Google Scholar 

  18. Nad, F. & Monceau, P. Dielectric response of the charge ordered state in quasi-one-dimensional organic conductors. J. Phys. Soc. Jpn 75, 051005 (2006).

    Article  Google Scholar 

  19. Starešinić, D., Biljaković, K., Lunkenheimer, P. & Loidl, A. Slowing down of the relaxational dynamics at the ferroelectric phase transition in one-dimensional (TMTTF)2AsF6 . Solid State Commun. 137, 241–245 (2006).

    Article  Google Scholar 

  20. Pinter, M. et al. Magnetic anisotropy and low-frequency dielectric response of weak ferromagnetic phase in κ-(BEDT−TTF)2Cu[N(CN)2]Cl, where BEDT-TTF is Bis(ethylenedithio)tetrathiafulvalene. Eur. Phys. J. B 11, 217–225 (1999).

    Google Scholar 

  21. Kagawa, F., Horiuchi, S., Tokunaga, M., Fujioka, J. & Tokura, Y. Ferroelectricity in a one-dimensional organic quantum magnet. Nature Phys. 6, 169–172 (2010).

    CAS  Google Scholar 

  22. Schrettle, F., Krohns, S., Lunkenheimer, P., Brabers, V. A. M. & Loidl, A. Relaxor ferroelectricity and the freezing of short-range polar order in magnetite. Phys. Rev. B 83, 195109 (2011).

    Article  Google Scholar 

  23. Joos, Ch. et al. Polaron melting and ordering as key mechanisms for colossal resistance effects in manganites. Proc. Natl Acad. Sci. USA 104, 13597–13602 (2007).

    Article  Google Scholar 

  24. Schrettle, F. et al. Switching the ferroelectric polarization by external magnetic fields in the spin = 1/2 chain cuprate LiCuVO4 . Phys. Rev. B 77, 144101 (2008).

    Article  Google Scholar 

  25. Naka, M. & Ishihara, S. Electronic ferroelectricity in a dimer Mott insulator. J. Phys. Soc. Jpn 79, 063707 (2010).

    Article  Google Scholar 

  26. Yamamoto, K. et al. Strong optical nonlinearity and its ultrafast response associated with electron ferroelectricity in an organic conductor. J. Soc. Phys. Jpn 77, 074709 (2008).

    Article  Google Scholar 

  27. Lunkenheimer, P. et al. Colossal dielectric constants in transition-metal oxides. Eur. Phys. J. Spec. Top. 180, 61–89 (2010).

    Article  Google Scholar 

  28. Takahide, Y. et al. Highly nonlinear current-voltage characteristics of the organic Mott insulator κ-(BEDT−TTF)2Cu[N(CN)2]Cl. Phys. Rev. B 84, 035129 (2011).

    Article  Google Scholar 

  29. Shimizu, Y., Miyagawa, K., Kanoda, K., Maesato, M. & Saito, G. Spin liquid state in an organic Mott insulator with a triangular lattice. Phys. Rev. Lett. 91, 107001 (2003).

    Article  CAS  Google Scholar 

  30. Wang, H. H. et al. Phase selectivity in the simultaneous synthesis of the T c = 12.8 K(0.3 kbar) organic superconductor κ-(BEDT−TTF)2Cu[N(CN)2]Cl or the semiconductor (BEDT-TTF) Cu[N(CN)2]2 . Chem. Mater. 4, 247–249 (1992).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank H-A. Krug von Nidda and H. Jeschke for helpful discussions. This work was supported by the Deutsche Forschungsgemeinschaft through the Transregional Collaborative Research Centers TRR 80 and TRR 49. Work at Argonne was supported by the US Department of Energy Office of Science, operated under contract no. DE-AC02-06CH11357.

Author information

Author notes

  1. Mariano de Souza

    Present address: Present address: IGCE, Unesp—Univ Estadual Paulista, Departamento de Fı´sica, Cx. Postal 178, CEP 13506-900 Rio Claro (SP), Brazil,

Authors and Affiliations

  1. Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany

    Peter Lunkenheimer, Stephan Krohns, Florian Schrettle & Alois Loidl

  2. Institute of Physics, Goethe-University Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt(M), Germany

    Jens Müller, Benedikt Hartmann, Robert Rommel, Mariano de Souza & Michael Lang

  3. Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan

    Chisa Hotta

  4. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA

    John A. Schlueter

Authors
  1. Peter Lunkenheimer
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jens Müller
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Stephan Krohns
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Florian Schrettle
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Alois Loidl
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Benedikt Hartmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Robert Rommel
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Mariano de Souza
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Chisa Hotta
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. John A. Schlueter
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Michael Lang
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.L., A.L., P.L. and J.M. conceived and supervised the project. J.A.S. grew the high-quality single crystals. B.H., J.M. and R.R. prepared the samples for the experiments. S.K., P.L. and F.S. performed the dielectric measurements and analysed the data. P.L. together with M.L. and J.M., wrote the paper with contributions from C.H., A.L., J.A.S. and M.d.S. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Peter Lunkenheimer or Mariano de Souza.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 976 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lunkenheimer, P., Müller, J., Krohns, S. et al. Multiferroicity in an organic charge-transfer salt that is suggestive of electric-dipole-driven magnetism. Nature Mater 11, 755–758 (2012). https://doi.org/10.1038/nmat3400

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat3400

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing