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Magnetization dynamics of irradiation-fabricated perpendicularly magnetized dots inside a softer magnetic matrix

  • T. Devolder (a1), M. Belmeguenai (a1), C. Chappert (a1), H. Bernas (a2) and Y. Suzuki (a3)...

Abstract

Global Helium ion irradiation can tune the magnetic properties of thin films, notably their magneto-crystalline anisotropy. Helium ion irradiation through nanofabricated masks can been used to produce sub-micron planar magnetic nanostructures of various types. Among these, perpendicularly magnetized dots in a matrix of weaker magnetic anisotropy are of special interest because their quasi-static magnetization reversal is nucleation-free and proceeds by a very specific domain wall injection from the magnetically “soft” matrix, which acts as a domain wall reservoir for the “hard” dot. This guarantees a remarkably weak coercivity dispersion. This new type of irradiation-fabricated magnetic device can also be designed to achieve high magnetic switching speeds, typically below 100 ps at a moderate applied field cost. The speed is obtained through the use of a very high effective magnetic field, and high resulting precession frequencies. During magnetization reversal, the effective field incorporates a significant exchange field, storing energy in the form of a domain wall surrounding a high magnetic anisotropy nanostructure's region of interest. The exchange field accelerates the reversal and lowers the cost in reversal field. Promising applications to magnetic storage are anticipated.

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[1] Thompson, D. and Best, J., IBM J. Res. Dev. 44(3) p311 (2000)
[2] Back, C. H. et al, Science 285, 864 (1999).
[3] Mathet, V., Devolder, T., Chappert, C., Ferré, J., Lemerle, S., Belliard, L., Guentherodt, G., J. Magn. Magn. Mat. 260, 295 (2003).
[4] Devolder, T., Chappert, C., Mathet, V., Bounabi, S., Suzuki, Y., Yokoyama, Y. and Bernas, H., IEEE Trans. Mag. 38(5), 2547, (2002).
[5]Visokay, M. R., Sinclair, R., Appl. Phys. Lett. 66(13), p1692 (1995)
[6] Maret, M. et al., Thin Film Solids 275 p 224, (1996)
[7] Rooney, O. W. et al. Phys. Rev. Lett 75(9) p1843 (1995)
[8] OOMMF: Micromagnetics simulation code developed mainly by Donahue, M. and Porter, D.. See http://math.nist.gov/oommf/
[9] Saito, N., et al. J. Phys. Soc. Jap, 19, 116 (1964); C. Kittel, Phys. Rev. 70, 965 (1946).
[10] Devolder, T., Chen, Y., Bernas, H., Chappert, C., Jamet, J.-P., Ferré, J., Cambril, E. Appl. Phys. Lett. 74, 22, p3383 (1999).
[11] Ziegler, J., Biersack, J. and Littmark, U., “The stopping of ions in matter”, Pergamon Press, N.Y. (1985); Software “SRIM” available at http://www.srim.org/.
[12] Devolder, T., Chappert, C., Mathet, V., Bernas, H., et al. J. Appl. Phys. 87(12) 8671 (2000).
[13] Hellwig, O. et al. Appl. Phys. Lett. 79(8) 1151 (2001).
[14] 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)
[15] Lemerle, S., Ferré, J., Chappert, C., V.Mathet, Giamarchi, T., Doussal, P. Le, Phys. Rev. Lett. 80, 849 (1998).
[16] Jamet, J.P., Lemerle, S., Meyer, P., Ferré, J., Bartenlian, B., Bardou, N., Chappert, C., Veillet, P., Rousseaux, F., Decanini, D., Launois, H., Phys. Rev. B 57, 14320 (1998).
[17] Landau, L., Lifshitz, E., Phys. Z Sowjetunion 8, 153 (1935); T.L. Gilbert, Phys. Rev. 100, 1243 (1955).
[18] Miltat, J., Aburquerque, G. and Thiaville, A. in Spin Dynamics in Confined Magnetic Structures, edited by Hillebrands, B. and Ounadjela, K. (Springer, Berlin, 2001).
[19] Maat, S., Takano, K., Parkin, S.S.P., Fulertton, E.E., Phys. Rev. Lett. 87(8), 087202 (2001)
[20] Devolder, T., Belmeguenai, M., Schumacher, H.W., Chappert, C., Suzuki, Y., Mat. Res. Soc. Symp. Procreeding of MRS Fall meeting, 2002.
[21] Devolder, T. and Chappert, C., submitted to Appl. Phys. Lett.
[22] Stoner, E. C. and Wohlfarth, E. P., Philos. Trans. R. Soc. London, Ser. A 240, 599 (1948).

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