Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 13: Poster Ia: Electron Theory (1); Magnetic Imaging (2,3); Thin Films (4-25); MSMA (26-33); Magn. Semiconductors (34-42); Magn. Half Metals and Oxides (43-60)
MA 13.34: Poster
Dienstag, 24. März 2009, 10:15–13:00, P1A
Temperature dependent domain wall dynamics in compressively strained GaMnAs — •Jan Honolka1, Liza Herrera Diez1, Reinhard Kremer1, Ernesto Placidi2, Fabrizio Arciprete2, and Klaus Kern1 — 1MPI für Festkörperforschung, Stuttgart — 2Dipartimento di Fisica, Universita di Roma 'Tor Vergata'
The correlation between carrier density and magnetic properties like Tc [1] or the magnetic anisotropy [2] in GaMnAs enables the tuning of magneto-transport properties and opens new ways for magneto-logic devices[3]. A full control over magnetic reversal dynamics mediated via nucleation and propagation of domain walls (DWs) is necessary. While magneto-transport measurements only give spatially averaged information about DW dynamics we use Kerr microscopy to track individual in-plane domains in space and time. Based on the energy landscape given by the interplay of bi- and uniaxial anisotropy contributions in compressively strained GaMnAs we are able to directly observe the nucleation of DWs and their shape and mobility. At low temperatures DW nucleation and propagation depend on the crystalline directions of the film with respect to the applied magnetic field [4]. We now show the temperature dependence of the dynamics which gives valuable information for controlling DW dynamics and for the development of single DW devices.
[1] T.Dietl et al., Science 287, 1019 (2000). [2] T.Dietl, H.Ohno, and F.Matsukura, Phys. Rev. B 63, 195205 (2001). [3] D.Chiba, M.Yamanouchi, F.Matsukura, H.Ohno, Science 301, 943 (2003). [4] L. Herrera Diez et al., Phys. Rev. B 78, 155310 (2008).