Berlin 2018 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 43: Magnetic textures I
MA 43.7: Vortrag
Donnerstag, 15. März 2018, 11:15–11:30, EB 407
SEMPA investigation of the Dzyaloshinskii-Moriya interaction in the single, ideally grown Co/Pt(111) interface — •Susanne Kuhrau, Edna C. Corredor, Fabian Kloodt-Twesten, Robert Frömter, and Hans Peter Oepen — Center for Hybrid Nanostructures, Universität Hamburg, Germany
The experimental investigation of the Dzyaloshinskii-Moriya interaction (DMI) of a single, ideally grown interface is compelling, as it allows the direct comparison with ab-initio calculations. We present a study of domains and domain walls in epitaxial, single-layer cobalt films on Pt(111) with a pseudomorphic, atomically flat interface by means of scanning electron microscopy with polarization analysis (SEMPA) [1], which is a surface-sensitive, vectorial imaging technique with a magnetic probing depth of < 5 atomic layers. Uncapped, thermally evaporated cobalt on a clean platinum single-crystal surface is imaged in situ in ultrahigh vacuum. For a cobalt thickness of 1.4 nm we observe Néel-like domain walls that show a fixed, counterclockwise sense of rotation indicating a strong DMI that originates from the single Co/Pt interface. From the observation of a pure Néel-like rotation, we derive a lower bound for the DMI strength of 0.5 × 10−3 J/m2, which gives a DMI energy per interface atom larger than 0.8 meV. An upper bound for the DMI energy of 4.3 meV per interface atom is derived from the observation of stable domains at the onset of ferromagnetism at 0.3-nm Co thickness, corresponding to an average Co coverage of 1.5 monolayers.
[1] E.C. Corredor et al., Phys. Rev. B 96, 060410(R), 2017