A theory of magnetization reversal in nanowires

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

Magnetization reversal in a ferromagnetic nanowire which is much narrower than the exchange length is believed to be accomplished through the thermally activated growth of a spatially localized nucleus, which initially occupies a small fraction of the total volume. To date, the most detailed theoretical treatments of reversal as a field-induced but noise-activated process have focused on the case of a very long ferromagnetic nanowire, i.e., a highly elongated cylindrical particle, and have yielded a reversal rate per unit length, due to an underlying assumption that the nucleus may form anywhere along the wire. But in a bounded-length (though long) cylindrical particle with flat ends, it is energetically favored for nucleation to begin at either end. We indicate how to compute analytically the energy of the critical nucleus associated with either end, i.e., the activation barrier to magnetization reversal, which governs the reversal rate in the low-temperature (Kramers) limit. Our treatment employs elliptic functions, and is partly analytic rather than numerical. We also comment on the Kramers prefactor, which for this reversal pathway does not scale linearly as the particle length increases, and tends to a constant in the low-temperature limit.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsZ. Gingl, J.M. Sancho, L. Schimansky-Geier, J. Kertesz
Pages48-57
Number of pages10
Volume5471
DOIs
StatePublished - 2004
EventNoise in Complex Systems and Stochastic Dynamics II - Maspalomas
Duration: May 26 2004May 28 2004

Other

OtherNoise in Complex Systems and Stochastic Dynamics II
CityMaspalomas
Period5/26/045/28/04

Fingerprint

Magnetization reversal
Nanowires
nanowires
magnetization
nuclei
Nucleation
elliptic functions
Chemical activation
Wire
Temperature
nucleation
wire
activation
energy

Keywords

  • Activation barrier
  • Ferromagnetic cylinder
  • Ferromagnetic nanowire
  • Kramers prefactor
  • Kramers theory
  • Landau-Lifshitz-Gilbert equation
  • Magnetization reversal
  • Néel-Brown theory
  • Weak spatiotemporal noise

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Maier, R. S. (2004). A theory of magnetization reversal in nanowires. In Z. Gingl, J. M. Sancho, L. Schimansky-Geier, & J. Kertesz (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 5471, pp. 48-57) https://doi.org/10.1117/12.553199

A theory of magnetization reversal in nanowires. / Maier, Robert S.

Proceedings of SPIE - The International Society for Optical Engineering. ed. / Z. Gingl; J.M. Sancho; L. Schimansky-Geier; J. Kertesz. Vol. 5471 2004. p. 48-57.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Maier, RS 2004, A theory of magnetization reversal in nanowires. in Z Gingl, JM Sancho, L Schimansky-Geier & J Kertesz (eds), Proceedings of SPIE - The International Society for Optical Engineering. vol. 5471, pp. 48-57, Noise in Complex Systems and Stochastic Dynamics II, Maspalomas, 5/26/04. https://doi.org/10.1117/12.553199
Maier RS. A theory of magnetization reversal in nanowires. In Gingl Z, Sancho JM, Schimansky-Geier L, Kertesz J, editors, Proceedings of SPIE - The International Society for Optical Engineering. Vol. 5471. 2004. p. 48-57 https://doi.org/10.1117/12.553199
Maier, Robert S. / A theory of magnetization reversal in nanowires. Proceedings of SPIE - The International Society for Optical Engineering. editor / Z. Gingl ; J.M. Sancho ; L. Schimansky-Geier ; J. Kertesz. Vol. 5471 2004. pp. 48-57
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