Skip to main content
SpringerLink
Log in

Thermal Activation in Permanent Magnets

  • Published:
JOM Aims and scope Submit manuscript

Abstract

The coercive field of permanent magnets decays with temperature. At non-zero temperatures, the system can overcome a finite energy barrier through thermal fluctuations. Using finite element micromagnetic simulations, we quantify this effect, which reduces coercivity in addition to the decrease of the coercive field associated with the temperature dependence of the anisotropy field, and validate the method through comparison with existing experimental data.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. O. Gutfleisch, M.A. Willard, E. Brück, C.H. Chen, S.G. Sankar, and J.P. Liu, Adv. Mater. 23, 821 (2011)

  2. S. Bance, H. Oezelt, T. Schrefl, G. Ciuta, N.M. Dempsey, D. Givord, M. Winklhofer, G. Hrkac, G. Zimanyi, O. Gutfleisch, T.G. Woodcock, T. Shoji, M. Yano, A. Kato, and A. Manabe, Appl. Phys. Lett. 104, 182408 (2014)

  3. R. Skomski, P. Kumar, G.C. Hadjipanayis, and D.J. Sellmyer, IEEE Trans. Magn. 49, 3229 (2013)

  4. H. Kronmuller, K.-D. Durst, and M. Sagawa, J. Magn. Magn. Mater. 74, 291 (1988)

  5. W.F. Brown, J. Appl. Phys. 30, S62 (1959)

  6. E.P. Wohlfarth, J. Phys. F 14, L155 (1984)

  7. D. Givord, P. Tenaud, and T. Viadieu, IEEE Trans. Magn. 24, 1921 (1988)

  8. V.M.T.S. Barthem, D. Givord, M.F. Rossignol, and P. Tenaud, J. Magn. Magn. Mater. 242, 1395 (2002)

  9. X.C. Kou, H. Kronmüller, D. Givord, and M.F. Rossignol, Phys. Rev. B 50, 3849 (1994)

  10. M.P. Sharrock, IEEE Trans. Magn. 26, 193 (1990)

  11. J.W. Harrell, IEEE Trans. Magn. 37, 533 (2001)

  12. D. Suess, S. Eder, J. Lee, R. Dittrich, J. Fidler, J. Harrell, T. Schrefl, G. Hrkac, M. Schabes, N. Supper, and A. Berger, Phys. Rev. B 75, 174430 (2007)

  13. G. Henkelman, B.P. Uberuaga, and H. Jónsson, J. Chem. Phys. 113, 9901 (2000)

  14. M.H. Ghandehari and J. Fidler, Mater. Lett. 5, 285 (1987)

  15. H. Nakamura, K. Hirota, M. Shimao, T. Minowa, and M. Honshima, IEEE Trans. Magn. 41, 3844 (2005)

  16. M.E. Schabes and H.N. Bertram, J. Appl. Phys. 64, 1347 (1988)

  17. M.E. Schabes, J. Magn. Magn. Mater. 95, 249 (1991)

  18. H.F. Schmidts and H. Kronmüller, J. Magn. Magn. Mater. 130, 329 (1994)

  19. H. Sepehri-Amin, T. Ohkubo, M. Gruber, T. Schrefl, and K. Hono, Scr. Mater. 89, 29 (2014)

  20. R. Dittrich, T. Schrefl, D. Suess, W. Scholz, H. Forster, and J. Fidler, J. Magn. Magn. Mater. 250, 12 (2002)

  21. R. Dittrich and T. Schrefl, IEEE Trans. Magn. 41, 3592 (2005)

  22. D. Suess, L. Breth, J. Lee, M. Fuger, C. Vogler, F. Bruckner, B. Bergmair, T. Huber, J. Fidler, and T. Schrefl, Phys. Rev. B 84, 224421 (2011)

  23. L. Exl, S. Bance, F. Reichel, T. Schrefl, H.P. Stimming, and N.J. Mauser, J. Appl. Phys. 115, 17D118 (2014)

  24. D. Suess, V. Tsiantos, T. Schrefl, J. Fidler, W. Scholz, H. Forster, R. Dittrich, and J.J. Miles, J. Magn. Magn. Mater. 248, 298 (2002)

  25. E. Weinan, W. Ren, and E. Vanden-Eijnden, J. Chem. Phys. 126, 164103 (2007)

  26. D. Givord, A. Lienard, P. Tenaud, and T. Viadieu, J. Magn. Magn. Mater. 67, L281 (1987)

  27. C. Vogler, F. Bruckner, B. Bergmair, T. Huber, D. Suess, and C. Dellago, Phys. Rev. B 88, 134409 (2013)

  28. W. Rave, K. Ramstöck, and A. Hubert, J. Magn. Magn. Mater. 183, 329 (1998)

  29. H. Sepehri-Amin, T. Ohkubo, S. Nagashima, M. Yano, T. Shoji, A. Kato, T. Schrefl, and K. Hono, Acta Mater. 61, 6622 (2013)

  30. S. Bance, B. Seebacher, T. Schrefl, L. Exl, M. Winklhofer, G. Hrkac, G. Zimanyi, T. Shoji, M. Yano, N. Sakuma, M. Ito, A. Kato, and A. Manabe, J. Appl. Phys. 116, 233903 (2014)

  31. E.C. Stoner and E.P. Wohlfarth. Philos. Trans. R. Soc. A 240, 599 (1948)

  32. S. Hirosawa, Y. Matsuura, H. Yamamoto, S. Fujimura, M. Sagawa, and H. Yamauchi, J. Appl. Phys. 59, 873 (1986)

  33. M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and S. Hirosawa, J. Appl. Phys. 57, 4094 (1985)

  34. M. Sagawa, S. Hirosawa, K. Tokuhara, H. Yamamoto, S. Fujimura, Y. Tsubokawa, and R. Shimizu, J. Appl. Phys. 61, 3559 (1987)

  35. M.J. Hawton, PhD Thesis, Durham University (1943)

  36. S Hock, Züchtung und magnetische Eigenschaften von (Fe, Al)\(_{14}\)(Nd, Dy)\(_2\)B-Einkristallen. PhD thesis, Universität Stuttgart (1988)

  37. K.-D. Durst and H. Kronmüller, J. Magn. Magn. Mater. 59, 86 (1986)

Download references

Acknowledgements

This paper is based on results obtained from the future pioneering program “Development of magnetic material technology for high-efficiency motors” commissioned by the New Energy and Industrial Technology Development Organization (NEDO). The authors would like to acknowledge funding support from the Replacement and Original Magnet Engineering Options (ROMEO) Seventh Framework Program (FP7).

Author information

Authors and Affiliations

  1. Department of Technology, St. Pölten University of Applied Sciences, 3100, St Pölten, Austria

    S. Bance, J. Fischbacher, A. Kovacs, H. Oezelt, F. Reichel & T. Schrefl

  2. Center for Integrated Sensor Systems, Danube University Krems, 2700, Wiener Neustadt, Austria

    T. Schrefl

Authors
  1. S. Bance
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. J. Fischbacher
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. Kovacs
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. H. Oezelt
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. F. Reichel
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. T. Schrefl
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to S. Bance.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bance, S., Fischbacher, J., Kovacs, A. et al. Thermal Activation in Permanent Magnets. JOM 67, 1350–1356 (2015). https://doi.org/10.1007/s11837-015-1415-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11837-015-1415-7

Keywords

Search

Navigation