Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 3: Methods: Scanning probe techniques I

O 3.5: Vortrag

Montag, 22. März 2010, 12:15–12:30, H32

Searching for spin contrast on NiO with Ni tips — •Florian Pielmeier and Franz J. Giessibl — Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany

Nickel atoms in the NiO(001) surface show antiferromagnetic ordering at room temperature resulting from indirect exchange interactions between neighbouring Ni 3d-electrons [1]. Frequency modulation atomic force microscopy, using extra stiff qPlus sensors, was used to probe the NiO(001) surface at room temperature. At tip-sample distances in the range of a few angstroms, the different spin orientations should provide detectable contributions to the short-range interaction forces between tip and sample. Nickel was used as the tip material as it is rather inert to oxygen and is widely used in spin polarized STM. Atomic resolution images with very good signal-to-noise ratio are presented, but similar to previous measurements with Co and NiO tips [2] evidence for spin contrast has not been found yet.

[1] D. Ködderitzsch, W. Hergert, W. M. Temmerman, Z. Szotek, A. Ernst, H. Winter: Phys. Rev. B 66, 064434 (2002)

[2] M. Schmid, J. Mannhart, F.J. Giessibl: Phys. Rev. B 77, 045402 (2008)