Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Magnetismus

MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)

MA 14.120: Poster

Dienstag, 25. März 2003, 15:15–19:15, Zelt

Thermally driven changes of the magnetic properties in epitaxial fcc-Fe — •Diego Repetto, Axel Enders, Dietrich Peterka, and Klaus Kern — Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany

The temperature dependence of the magnetic properties of ultrathin fcc-iron films grown epitaxially on Cu(100) at low temperatures are investigated by MOKE and in-situ Kerr microscopy. We find that the magnetic anisotropy and the coercivity change partly reversible and irreversible with temperature. From the thermally induced reversible shift of the spin reorientation transition (SRT), as observed on an Fe wedge directly, the temperature dependence of the surface anisotropy constant K(T) is extracted. The irreversible shift of the SRT, as well as the increase of the coercivity of the iron films, are correlated with the increasing Fe island size observed in VT-STM experiments during annealing. The enhancement of the coercivity after annealing is discussed in terms of domain wall energy inhomogeneities provided by the islands. Thus, the studies underline the strong correlation between film structure and magnetic properties. The temperature dependence of the Barkhausen length is determined from magnetic viscosity measurements. The increase of the Barkhausen length with temperature from 80 nm at 120 K to 240 nm at 300 K is fully reversible and therefore independent of the film morphology.