Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 27: Spindynamik II
MA 27.4: Vortrag
Dienstag, 8. März 2005, 16:00–16:15, TU H1012
Limitations of the Landau-Lifshitz-Equation and spin-pump effects in magnetic nanostructures — •K. Lenz1, E. Kosubek1, T. Toliński2, K. Baberschke1, and A. Janossy3 — 1Inst. f. Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin — 2Institute of Molecular Physics, PAS; Smoluchowskiego 17, 60-179 Poznań, Poland — 3Department of Experimental Physics, Institute of Physics, Budapest University of Technology and Economics, 1521 Budapest, Hungary
Two mechanisms have been the topic of recent discussions concerning the precessional damping at interfaces of ferromagnetic to nonmagnetic materials: (i) The magnon-magnon scattering, with origin in surface or interface defects. (ii) The spin-pump effect, i.e. the transfer of angular momentum from the precessing magnetization excited by ferromagnetic resonance to the conduction electrons of a non-magnetic layer. The commonly used Landau-Lifshitz-Gilbert equation is insufficient to describe transverse scattering within magnetic excitations. In addition to previous results [1] we present FMR data up to 230 GHz showing the importance of two-magnon scattering. Secondly, the linewidth analysis of Ni/Cu/Ni trilayer FMR for parallel and perpendicular alignment of the Ni magnetization shows distinct narrowing as function of the orientation of the external field, which will be discussed in terms of spin-pump effects [2].
Supported by DFG (Sfb 290, TP A2).
[1] J. Lindner et al., Phys. Rev. B 68, 060102(R) (2003)
[2] K. Lenz et al., Phys. Rev. B 69, 144422 (2004)