Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 8: Surface Magnetism
MA 8.3: Vortrag
Montag, 27. März 2006, 15:30–15:45, HSZ 103
XMCD at O K edge of Fe, Co, and Ni films grown with O surfactant — •C. Sorg1, N. Ponpandian1, M. Bernien1, J. Kurde1, K. Baberschke1, R. Q. Wu2, and H. Wende1 — 1Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany — 2Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
We have grown ultrathin ferromagnetic films of Fe, Co, and Ni with oxygen as a surfactant on Cu(100) and studied the systematics of their near edge X-ray absorption fine structure (NEXAFS) and X-ray magnetic circular dichroism (XMCD) at the O K edge [1,2]. It was shown earlier that using O as a surfactant improves the growth of these films toward a more layer-by-layer one [3]. Angular-dependent NEXAFS measurements at the O K edge give final evidence that the O does not form a bulk-like oxide with the 3d ferromagnet, and the O atoms stay on top of the growing film. The spectral features of the NEXAFS are identified with the help of density functional calculations. Due to the hybridization with the ferromagnet, the O acquires an induced magnetic moment that can be probed by XMCD at the O K edge. The calculations reproduce the experimental spectra very well and yield spin and orbital moments of the ferromagnetic films as well as the induced moments of the oxygen surfactant [2]. – Supported by BMBF (05 KS4 KEB 5).
[1] C. Sorg et al., Surf. Sci. 565, 197 (2004).
[2] C. Sorg et al., Phys. Rev. B, submitted (2005).
[3] R. Nünthel et al., Surf. Sci. 531, 53 (2003); ibid. 566-568, 100 (2004).