Letter | Published:

Relaxor ferroelectricity and colossal magnetocapacitive coupling in ferromagnetic CdCr2S4

Abstract

Materials in which magnetic and electric order coexist—termed ‘multiferroics’ or ‘magnetoelectrics’—have recently become the focus of much research1,2,3,4. In particular, the simultaneous occurrence of ferromagnetism and ferroelectricity, combined with an intimate coupling of magnetization and polarization via magnetocapacitive effects, holds promise for new generations of electronic devices. Here we present measurements on a simple cubic spinel compound with unusual, and potentially useful, magnetic and electric properties: it shows ferromagnetic order coexisting with relaxor ferroelectricity (a ferroelectric cluster state with a smeared-out phase transition), both having sizable ordering temperatures and moments. Close to the ferromagnetic ordering temperature, the magnetocapacitive coupling (characterized by a variation of the dielectric constant in an external magnetic field) reaches colossal values, approaching 500 per cent. We attribute the relaxor properties to geometric frustration, which is well known for magnetic moments but here is found to impede long-range order of the structural degrees of freedom that drive the formation of the ferroelectric state.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1

    Kimura, T. et al. Magnetic control of ferroelectric polarization. Nature 426, 55–58 (2003)

  2. 2

    Goto, T., Kimura, T., Lawes, G., Ramirez, A. P. & Tokura, Y. Ferroelectricity and giant magnetocapacitance in perovskite rare-earth manganites. Phys. Rev. Lett. 92, 257201 (2004)

  3. 3

    Hur, N. et al. Electric polarization in a multiferroic material induced by magnetic fields. Nature 429, 392–395 (2004)

  4. 4

    Lottermoser, Th. et al. Magnetic phase control by an electric field. Nature 430, 541–544 (2004)

  5. 5

    Hill, N. A. Why are there so few magnetic ferroelectrics? J. Chem. Phys. B 104, 6694–6709 (2000)

  6. 6

    Smolenskii, G. A. & Chupis, I. E. Ferroelectromagnets. Sov. Phys. Usp. 25, 475–493 (1983)

  7. 7

    Verwey, J. E. W. Electronic conduction of magnetite (Fe3O4) and its transition point at low temperature. Nature 144, 327–328 (1939)

  8. 8

    Fritsch, V. et al. Spin and orbital frustration in MnSc2S4 and FeSc2S4 . Phys. Rev. Lett. 92, 116401 (2004)

  9. 9

    Fichtl, R., Tsurkan, V., Lunkenheimer, P., Hemberger, J., Fritsch, V., Krug von Nidda, H.-A., Scheidt, E.-W. & Loidl, A. Orbital freezing and orbital glass state in FeCr2S4 . Phys. Rev. Lett. 94, 027601 (2005)

  10. 10

    Baltzer, P. K., Lehmann, H. W. & Robbins, M. Insulating ferromagnetic spinels. Phys. Rev. Lett. 15, 493–495 (1965)

  11. 11

    Göbel, H. Local lattice distortions in chromium chalcogenide spinels at low temperatures. J. Magn. Magn. Mater. 3, 143–146 (1976)

  12. 12

    Martin, G. W., Kellog, A. T., White, R. L. & White, R. M. Exchangestriction in CdCr2S4 and CdCr2Se4 . J. Appl. Phys. 40, 1015–1016 (1969)

  13. 13

    Harbeke, G. & Pinch, H. Magnetoabsorption in single-crystal semiconducting ferromagnetic spinels. Phys. Rev. Lett. 17, 1090–1092 (1966)

  14. 14

    Wakamura, K. & Arai, T. Effect of magnetic ordering on phonon parameters for infrared active modes in ferromagnetic spinel CdCr2S4 . J. Appl. Phys. 63, 5824–5829 (1988)

  15. 15

    Lehmann, H. W. & Robbins, M. Electrical transport properties of the insulating ferromagnetic spinels CdCr2S4 and CdCr2Se4 . J. Appl. Phys. 37, 1389–1390 (1966)

  16. 16

    Samara, G. A. The relaxation properties of compositionally disordered ABO3 perovskites. J. Phys. Condens. Matter 15, R367–R411 (2003)

  17. 17

    Cross, L. E. Relaxor ferroelectrics. Ferroelectrics 76, 241–267 (1987)

  18. 18

    Kamba, S. et al. Dielectric dispersion of relaxor PLZT ceramics in the frequency range 20 Hz-100 THz. J. Phys. Condens. Matter 12, 497–519 (2000)

  19. 19

    Lunkenheimer, P. et al. Origin of apparent colossal dielectric constants. Phys. Rev. B 66, 052105 (2002)

  20. 20

    Austin, I. G. & Mott, N. F. Polarons in crystalline and non-crystalline materials. Adv. Phys. 18, 41–103 (1969)

  21. 21

    Callen, E. Optical absorption edge of magnetic semiconductors. Phys. Rev. Lett. 20, 1045–1048 (1968)

  22. 22

    Grimes, N. W. Off-centre ions in compounds with spinel structure. Phil. Mag. 26, 1217–1226 (1972)

  23. 23

    Ramirez, A. P. in Handbook of Magnetic Materials Vol. 13 (ed. Buschow, K. H. J.) 423–520 (Elsevier, Amsterdam, 2001)

  24. 24

    Ramirez, A. P. Magic moments. Nature 421, 483 (2003)

  25. 25

    Mary, T., Evans, J. S. O., Vogt, T. & Sleight, A. W. Negative thermal expansion from 0.3 to 1050 K in ZrW2O8 . Science 272, 90–92 (1996)

  26. 26

    Cao, D., Bridges, F., Kowach, G. R. & Ramirez, A. P. Frustrated soft modes and negative thermal expansion in ZrW2O8 . Phys. Rev. Lett. 89, 215902 (2002)

  27. 27

    Knorr, K. & Loidl, A. Anomalous diffraction profiles of alkali-halide-alkali-cyanide mixed crystals. Phys. Rev. Lett. 57, 460–462 (1986)

  28. 28

    Höchli, U. T., Knorr, K. & Loidl, A. Orientational glasses. Adv. Phys. 39, 405–615 (1990)

  29. 29

    Lunkenheimer, P., Schneider, U., Brand, R. & Loidl, A. Glassy dynamics. Contemp. Phys. 41, 15–36 (2000)

Download references

Acknowledgements

This work was supported partly by the Deutsche Forschungsgemeinschaft via the Sonderforschungsbereich 484 and partly by the BMBF via VDI/EKM.

Author information

Correspondence to P. Lunkenheimer.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Further reading

Figure 1: Magnetic and dielectric characterization of CdCr2S4.
Figure 2: Magnetocapacitive behaviour of CdCr2S4.
Figure 3: Thermo-remanent polarization versus temperature.

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.