Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 41: Inorganic/Organic Interfaces
O 41.9: Poster
Dienstag, 17. März 2015, 18:15–21:00, Poster B
Inelastic Excitations in Rare-Earth-Based Metal-Organic Complexes — •Daniela Rolf1, Paul Stoll1, Tobias R. Umbach1, Janina N. Ladenthin1, Matthias Bernien1, Constantin Czekelius1,2, Wolfgang Kuch1, and Katharina J. Franke1 — 1Freie Universität Berlin — 2Heinrich-Heine-Universität Düsseldorf
Rare-earth atoms with a partially filled f shell exhibit interesting magnetic properties due to their large magnetic anisotropy. Embedded in a molecular environment, they are prime examples of single-molecule magnets. The Dy-(aquo)-tris(1,1,1-trifluoro-4-(2-thienyl)-2,4-butanedionate) (Dy-t-TTB) molecule is a 3-dimensional complex, in which the Dy center is coordinated by three organic ligands. Within this complex, Dy has the oxidation state +3, leading to a total angular momentum of J = 15/2. Due to magnetic anisotropy, the degeneracy of the different MJ levels of the ground state is partially lifted, allowing for transitions between the sublevels. Employing low-temperature STM we show that Dy-t-TTB on a Au(111) surface forms densely packed self-assembled islands. Tunneling spectra show an inelastic step at ±7.7 meV. To identify the origin of this feature, we compare to spectra taken on Gd-t-TTB, showing inelastic steps at the same energy. Gd3+ has a half-filled f shell and is not expected to show any magnetic anisotropy. Hence, we conclude that the inelastic step is not due to transitions between the anisotropy-split spin states, but can be explained by the excitation of vibrations. Furthermore, we observe the tip-induced rotation of the upper ligand of Dy-t-TTB and Gd-t-TTB.