Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 2: Bio- and Molecular Magnetism

MA 2.9: Vortrag

Montag, 22. März 2010, 12:45–13:00, H10

Preparation and characterization of Mn₆Cr single-molecule-magnets on surfaces — •Marc Sacher¹, Andreas Helmstedt¹, Aaron Gryzia¹, Peter Koop¹, Sebastian Steppeler¹, Norbert Müller¹, Armin Brechling¹, Ulrich Heinzmann¹, Veronika Höke², Thorsten Glaser², Mikhail Fonin³, and Ulrich Rüdiger³ — ¹Fak. f. Physik, Uni Bielefeld — ²Fak. f. Chemie, Uni Bielefeld — ³Fak. f. Physik, Uni Konstanz

The single-molecule-magnet (SMM) Mn₆Cr consists of two bowl-shaped Mn₃-salen complexes, bridged by a complex containing a Cr atom. Three counterions are coupled to the SMM to ensure charge neutrality. To study the influence of the molecule-substrate-interaction on the electronic and the magnetic properties a homogeneous preparation of the SMM on the substrate is necessary. The preparation is done by dropping SMM, dissolved in methanol with certain concentration. Depending on the choice of the substrate, the Mn₆Cr concentration, the substrate inclination and the droplet size the arrangement of the SMM strongly varies. This will be visualized in videos of the drying process obtained by optical microscopy with a magnification of up to 1000. The electronic properties of the deposited SMM are investigated by X-ray absorption spectroscopy. These properties change with exposure time due to a low stability of the SMM against X-rays. These changes can be accelerated or slowed down via the choice of the counterions and the SMM concentration on the substrate. Possible reasons will be discussed.