Dresden 2003 – scientific programme
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MA: Magnetismus
MA 18: Spindynamik / Ummagnetisierungsvorg
änge
MA 18.11: Talk
Wednesday, March 26, 2003, 17:45–18:00, HSZ/401
Ultrafast magnetization dynamics in thin iron films: phonon and magnon contributions in the time-resolved MOKE — •P. Guderian1, T. Kampfrath1, M. M*nzenberg1, R. G. Ulbrich1, B. Sass2, F. Leuenberger2, W. Felsch2 und J. S. Moodera3 — 1IV. Phys. Inst., Universität Göttingen — 2I. Phys. Inst., Universität Göttingen — 3Francis Bitter Magnet Laboratory, MIT
Magnetization dynamics of magnetic nanostructures in the sub ns regime is a
special field of interest for ultrafast memory or spin-logic elements. What
is the time scale on which magnetization can be manipulated?
Ti:Sapphire
lasers are an ultimate tool to study magnetization dynamics on the
ultra-fast time scale: The the variation of the delay between pump and
probe pulse enables to probe the dynamics from ps to a few 100 ps
locally. We present pump-probe measurements on Fe thin films and show how
to partly separate the effects of the variation of the optical properties
and the
change in magnetization as proposed by Kampfrath[1]. The signature of
phonons in the optical contribution and the magnetic precession observed in
the purely magnetic signal will be separated and the origin will be
discussed. Simulations using the Landau-Lifshitz-Gilbert equation enable to
extract an intrinsic Gilbert damping parameter
[1]T. Kampfrath et al.,
Phys. Rev. B 65, 104429 (2002)