The inside of C80: A cornucopia for molecular magnetism
- Datum: 30.11.2017
- Uhrzeit: 17:15
- Vortragende(r): Prof. Thomas Greber
- Universität Zürich, Schweiz
- Ort: Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Theodor-Lieser-Str. 9, 06120 Halle
- Raum: Gustav-Mie-Hörsaal
Single molecule magnets are molecules with open electron shells that maintain their spin orientation for a long time compared to the Bohr time period.Endohedral molecules, like C80 that contain open shell lanthanides are a particularly interesting class of single molecule magnets. For the case of R3N@C80, where R is a trivalent rare earth atom, in principle 560 different molecules may be synthesized, and this signifies a real cornucopia for the investigation of the interaction of up to 3 different magnetic moments.With x-ray circular magnetic dichroism (XMCD) we may look inside the Fullerenes and assign the magnetism to the open 4f shell in lanthanide ions .With a superconducting quantum interference device (SQUID) it is possible to infer the interaction of two and three Dy ions inside C80, where it turns out that an exchange and dipole barrier protects the ground state of Dy2ScN@C80, while the ground state of Dy3N@C80 is frustrated .The talk shall illustrate that we can address with the molecular precision of the chemists the magnetic interaction between single atoms, and learn lessons needed for the understanding of spin physics at the nanometer scale. In particular I will address the interaction across the C80 carbon shell that imposes endohedral ordering, and a way to switch the orientation of the endohedral units with magnetic fields.
- R. Westerström et al. An Endohedral Single-Molecule Magnet with Long Relaxation Times: DySc2N@C80, J. Am. Chem. Soc. 134, 9840 (2012).
- R. Westerström et al.
Tunneling, remanence, and frustration in dysprosium-based endohedral
single-molecule magnets, Phys. Rev. B 89, 060406(R) (2014).