Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 33: Nanostructures at Surfaces: Metals, Oxides and Semiconductors I

O 33.9: Vortrag

Dienstag, 21. März 2017, 12:30–12:45, REC/PHY C213

A DFT-based investigation of 3d adatoms and small clusters on Cu(111): magnetism and AFM images — •Svitlana Polesya¹, Sergiy Mankovsky¹, Hubert Ebert¹, and Franz J. Giessibl² — ¹LMU München, Dept. Chemie, München, Germany — ²Inst. Experimentelle Physik, Univ. Regensburg, Germany

Density Functional Theory (DFT) based calculations have been performed in order to investigate the forces on a CO tip in the vicinity of 3d atoms deposited on Cu(111) surface. For this, a full structure relaxation of adatoms and surrounding surface atoms has been taken into account. In the case of an Mn adatom the crucial role of relaxation to stabilize its magnetic state is shown. The effects of local electronic correlations have been investigated via GGA+U calculations. The forces on a CO tip obtained within DFT calculations are discussed in comparison with experimental AFM images. It is found that all magnetic adatoms reveal a three fold symmetry of the lateral AFM-image as observed experimentally for a Fe adatom [1]. The relaxed geometry and magnetic moments distribution have been also calculated for larger Fe clusters (up to 10 atoms). For 10-atom Fe cluster the hexagonal rim shape of the experimental AFM image is obtained. Surprisingly, the force maxima do not fully coincide with the positions of ’hexagon’ atoms but are located between these atoms, in full agreement with experiment [2].

[1] M. Emmrich, F. Huber et al., Science 348, 308 (2015)

[2] S. Matencio, F. Huber, J. Berwanger, M. Emmrich, A. J. Weymouth, F. J. Giessibl. Unpublished.