Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65
MA 20.8: Poster
Montag, 7. März 2005, 14:00–18:00, Poster TU C
Temperature dependence of the magnetization in ultrathin epitaxial FeCo layers with vanishing crystal anisotropy — •Matthias Sperl, Wolfgang Kipferl, Martin Dumm und Günther Bayreuther — Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg
Epitaxial ultrathin Fe xCo 1−x(001) layers were grown with molecular beam epitaxy on Au(001) surfaces. The alloy composition was chosen in the range of the composition dependent in-plane reorientation transition at about 30% Co [1]. Epitaxial growth was achieved by using an Fe seed layer and Au buffer layer on GaAs(001). Epitaxial quality and surface structure were verified in-situ by RHEED. The magnetic properties were investigated by MOKE and SQUID magnetometry between 10 and 400 K. All films show a reduced four-fold anisotropy compared to Fe layers on Au(001) at room temperature and a negligible uniaxial in-plane anisotropy. The samples were studied with respect to the critical behavior at the phase transition and thermal excitations due to spinwaves. This allows the determination of the influence of a reduced in-plane anisotropy on the temperature dependence of the spontaneous magnetization MS which is discussed in connection with the increased exchange interaction of the used FeCo alloy compared to Fe.
[1] G. Bayreuther et. al., J. Appl. Phys. 93, 8230 (2003)