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MA: Magnetismus
MA 4: Magnetic Materials I
MA 4.10: Vortrag
Montag, 27. März 2006, 12:30–12:45, HSZ 401
First-principles investigation of Co wires at Pt(111) step-edges — •Gustav Bihlmayer1, Stéphanie Baud2, Christophe Ramseyer2, and Stefan Blügel1 — 1Forschungszentrum Jülich, Institut für Festkörperforschung, Jülich, Germany — 2Laboratoire de physique moléculaire, UMR CNRS 6624, Besançon, France
We investigate Co wires of different width deposited on step-edges of Pt(111), simulated by a Pt(664) surface. The calculations were preformed within the framework of the density functional theory using the FLAPW method. An adsorbed Co chain showed a magnetic anisotropy energy (MAE) and easy axis in good agreement with experimental data [1]. Inclusion of relaxations turned the easy axis even more in the direction of the upper terrace and quenched the orbital moments and their anisotropy. While this seems unfavorably in comparison to experiment, we argue – based on a decomposition of the contribution to the MAE of the different atoms (Pt or Co) – that relaxations might be an essential part of the calculations including orbital polarizations. We investigated also the evolution of the easy axes and the MAE as function of the number of Co chains deposited on the stepped surface. The results nicely compare to those obtained experimentally [2]. We present a simple model to account for the experimentally observed oscillations of the easy axis.
[1] P.Gambardella et al. Nature 416, p.301 (2002)
[2] P.Gambardella et al. Phys. Rev. Lett. 93 077203 (2004)