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 20.9: Poster
Montag, 7. März 2005, 14:00–18:00, Poster TU C
Magnetic saturation and anisotropy in FeCo alloy films grown on Pd(001) — •A. Winkelmann, M. Przybylski, Y. Shi, J. Barthel, and J. Kirschner — Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle
Theoretical first-principles calculations for tetragonally distorted FexCo1−x alloys predict a high saturation magnetization and a high uniaxial magnetic anisotropy energy at specific values of the lattice distortion c/a and alloy composition x [1]. An unusually large magnetic anisotropy energy is expected for the Fe40Co60 alloy at a c/a ratio of about 1.2. Comparable tetragonal distortions in Fe and Co films have been observed on Pd(001). This suggests the deposition of FexCo1−x alloy films on Pd(001) by molecular beam epitaxy.
For Fe40Co60 at a film thickness of 3 monolayers (ML), scanning tunneling microscopy shows rough film surfaces. This is due to a structural transition caused by the large lattice misfit between the Pd substrate and the alloy film. Intensity oscillations in reflection high energy electron diffraction indicate a change in the growth mode after 2 ML of Fe40Co60. Low energy electron diffraction (LEED) patterns confirm a pseudomorphic growth of the Fe40Co60 film. Measurements of energy resolved LEED intensities point to the existence of a tetragonal distortion perpendicular to the film plane. Hysteresis loops were taken using the magneto-optical Kerr effect (MOKE). The results of the MOKE analysis are discussed in comparison to the results obtained for the Fe/Pd(001) and Co/Pd(001) systems.
[1] T. Burkert et al. , Phys. Rev. Lett. 93, 027203 (2004)