Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 7: Spin-Dynamics/ Spin-Torque II
MA 7.15: Vortrag
Montag, 23. März 2009, 19:00–19:15, HSZ 04
Investigating the Spin Dynamics in Nanostructures at Finite Temperature — •David Bauer, Samir Lounis, Phivos Mavropoulos, and Stefan Bluegel — Institut für Festkörperforschung and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
Magnetic nanoparticles are promising candidates for future information
storage. We developed a spin dynamics code and investigated the
dynamics of the magnetization in nanoscale systems on the basis of a
classical spin model including Heisenberg exchange, magnetic
anisotropy, external magnetic fields and dipole-dipole
interaction. The spin-system is coupled to a heatbath through a
stochastic force within the Langevin approach [1]. This requires the
solution of the stochastic Landau-Lifschitz equations.
Thermodynamical properties are shown to be in excellent agreement to
those obtained by Monte Carlo simulations. The complexity O(n2) of the
direct evaluation of the dipolar interaction was reduced to O(nlogn)
by the use of multipole methods. Preliminary results are presented on
the switching time of different sized nano-islands which are in
agreement to the Arrhenius-Néel-law.
This work was supported by the ESF EUROCORES Programme SONS under contract N. ERAS-CT-2003-980409 and
the Priority Programme SPP1153 of the DFG grant Bl 444/8-1.
[1] V. P. Antropov, S. V. Tretyakov, and B. N. Harmon, J. Appl. Phys. 81, 3961 (1997).