Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 8: Magnetic Imaging

MA 8.2: Vortrag

Montag, 25. Februar 2008, 15:30–15:45, H 1012

spin-polarized scanning tunneling spectroscopy on individual magnetic adatoms — •lihui zhou, focko meier, jens wiebe, and roland wiesendanger — Institue of Applied Physics, Hamburg University, Jungiusstrasse 11, D-20355 Hamburg, Germany

Using spin-polarized scanning tunneling spectroscopy the spin-resolved electronic states of single Co adatoms on Pt(111) are studied as a function of an external magnetic field, which allows to access the magnetization curves of individual adatoms directly. Surprisingly, we find that the adatoms show paramagnetic behaviour at very low temperature despite of their large magnetic anisotropy [1]. Although the adatoms have identical electronic configurations the magnetic field necessary for saturation shows a strong variation from atom to atom. We ascribe this effect to their mutual RKKY interaction. Indeed, we find experimental evidence for the magnetic interaction between the adatoms and a Co monolayer stripe, which oscillates back and forth between ferromagnetic and antiferromagnetic coupling over a distance of several nanometers.

[1] P. Gambardella et al., Science 300, 1130 (2003)