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Precessional strategies for the ultrafast switching of soft and hard magnetic nanostructures

Published online by Cambridge University Press:  10 February 2011

T. Devolder ,
M. Belmeguenai ,
H. W. Schumacher ,
C. Chappert  and
Y. Suzuki
T. Devolder
Affiliation:
Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, FRANCE.
M. Belmeguenai
Affiliation:
Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, FRANCE.
H. W. Schumacher
Affiliation:
Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, FRANCE.
C. Chappert
Affiliation:
Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, FRANCE.
Y. Suzuki
Affiliation:
Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, FRANCE.
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Abstract

We discuss the precessional, quasi-ballistic switching of magnetization in magnetic nanostructures. In soft spin-valve cells, fast and energy-cost effective magnetization switching can be triggered by a transverse field pulse of moderate amplitude, below the in plane anisotropy field, because of an amplification effect brought by the demagnetizing field at the early stage of the reversal. The same effect is no more possible in hard nanomagnets with perpendicular easy magnetization axis. We propose a new type of nanostructured magnetic device, designed to overcome this limitation. The speed is obtained through the use of a very high effective magnetic field, obtained by incorporating a significant exchange field which stores the energy in the form of a constrained domain wall surrounding a region of high magnetic anisotropy. This stored energy is partially available to accelerate the magnetization reversal in a precessional scenario. We illustrate the concept by studying numerically a model system. The key parameter for the reversal is the ratio of the domain wall width to the structure lateral dimension. Possible routes for device preparation are discussed. Promising application to magnetic storage are anticipated.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 746: Symposia Q/R – Magnetoelectronics-Novel Magnetic Phenomena in Nanostructures – Advanced Characterization of Artificially Structured Magnetic Materials , 2002 , Q8.4
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Spin Dynamics in Confined Magnetic Structures, Hillebrands, B. and Ounadjela, K. (Springer, Berlin, 2001).Google Scholar
2. Choi, B. C. et al., Phys. Rev. Lett. 86, 728 (2001);Google Scholar
Hiebert, W. K., Ballentine, G. E., and Freeman, M. R., Phys. Rev. B 65, 140404(R) (2002)Google Scholar
3. Koch, R. H. et al., Phys. Rev. Lett. 81, 4512 (1998)Google Scholar
4. Landau, L., Lifshitz, E., Phys. Z Sowjetunion 8, 153 (1953);Google Scholar
Gilbert, T.L., Phys. Rev. 100, 1243 (1955).Google Scholar
5. “Classical and quantum magnetization reversal studied in nanometer-sized particles and clusters”, Wernsdorfer, W.. To be publ. in Advances in Chemical Physics (Wiley Ed.), 2003.Google Scholar
6. Gerrits, Th., Van Den Berg, H. A. M., Hohlfeld, J., Bär, L., Rasing, Th., Nat. 418, 6897 (2002)Google Scholar
7. Schumacher, H.W., Chappert, C., Crozat, P., Sousa, R. C., Freitas, P. P., Miltat, J., Fassbender, J., and Hillebrands, B., Phys. Rev. Lett. 90(1), 017201 (2003).Google Scholar
8. Kaka, S. and Russek, S. E., Appl. Phys. Lett. 80, 2958 (2002).Google Scholar
9. Schumacher, H.W., Chappert, C., Sousa, R. C., Freitas, P. P., and Miltat, J., Phys. Rev. Lett. 90(1) 017204 (2003).Google Scholar
10. Chappert, C., Bernas, H., Ferré, J., Kottler, V., Jamet, J.P., Chen, Y., Cambril, E., Devolder, T., Rousseaux, F., Mathet, V. and Launois, H., Science 280, 1919 (1998).Google Scholar
11. Miltat, J., Aburquerque, G. and Thiaville, A. in Spin Dynamics in Confined Magnetic Structures, edited by Hillebrands, B. and Ounadjela, K. (Springer, Berlin, 2001).Google Scholar
12. Bauer, M. et al., Phys. Rev. B 61(5) p3410 (2000)Google Scholar
13. Schumacher, et al., Appl. Phys. Letters 80, 3781 (2002)Google Scholar
14. Kittel, C., Introduction to Solid State Physics, 5th ed., Wiley, New York, 1976.Google Scholar
15. tStoner tand, E. tC., tWohlfarth, tE. tP., Philos, . Trans. R. Soc. London, Ser. A 240, 599 (1948)Google Scholar
16. chang, C-R., Yang, J-S., Phys. Rev. B 54(17) pp11957 (1996).Google Scholar
17. “Magnetization precession in confined geometry: physical and numerical aspects”. PhD thesis of Gonçalo M. B. Albuquerque, Orsay, July 2002.Google Scholar
18. Maat, S., Takano, K., Parkin, S.S.P., Fulertton, E.E., Phys. Rev. Lett. 87(8), 087202(2001)Google Scholar
19. Wall mobilities in similar Pt/Co systems gave α=0.2. S. Lemerle, private communication.Google Scholar
20. Devolder, T. et al., Appl. Phys. Lett. 74, 22, p3383 (1999)Google Scholar
21. Li, S.P., Lew, W.S., Bland, J.A.C., Lopez-Diaz, L., Liaz, C.A.F, Natali, M., Chen, Y., Phys. Rev. Lett. 88(8), 087202 (2002).Google Scholar