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O: Fachverband Oberflächenphysik

O 58: Organic-Inorganic Systems III: Metal-Organics

O 58.8: Talk

Wednesday, March 9, 2016, 17:00–17:15, S054

Synthesis of Organometallic Sandwich Complexes and Nanowires on Graphene — •Felix Huttmann, Nicolas Schleheck, Merve Seçkin, and Thomas Michely — II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany

Organometallic sandwich-molecular nanowires of europium-cyclooctatetraene (EuCot) and vanadium-benzene (VBz) have been theoretically predicted to have interesting electronic structures: Semiconducting and ferromagnetic (EuCot) [1] or half-metallic and ferromagnetic with full spin polarization of the conduction band (VBz) [2]. They thus have potential for efficient spin filters. Here, we have pursued their growth from the constituent vapors on an inert graphene surface, and investigated the samples in situ using scanning tunneling microscopy. EuCot nanowires form readily, and by varying the growth conditions, we find a rich spectrum of morphologies, from a disordered, spaghetti-like growth to highly ordered, anisotropically shaped, two-dimensional crystallites made of wire bundles. In these bundles, the wires are offset against their nearest neighbors to allow the wires to hook into each other, and where wire bundles bend, a characteristic bending angle is often observed to accommodate this. In contrast, for VBz only sandwich molecules of composition VBz₂ could be produced, but no wires. VBz₂ molecules form overlayers and desorb at around room temperature.

[1] Ke Xu et al., J. Chem. Phys. 131, 104704 (2009)

[2] V. V. Maslyuk et al., Phys. Rev. Lett. 97, 097201 (2006)