Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 3: Bio- and Molecular Magnetism

MA 3.3: Vortrag

Montag, 14. März 2011, 11:30–11:45, HSZ 401

Inelastic Neutron Scattering Studies on the 3d-4f Heterometallic Single-Molecule Magnet Mn₂Nd₂ — •Joscha Nehrkorn¹, Muhammad Nadeem Akhtar², Ruggero Milazzo¹, Stefan Stuiber¹, Hannu Mutka³, Yanhua Lan², Annie K. Powell², and Oliver Waldmann¹ — ¹Physikalisches Institut, Universität Freiburg, Germany — ²Institut für anorganische Chemie, Universität Karlsruhe, KIT, Germany — ³Institut Laue-Langevin, Grenoble, France

The discovery of slow relaxation and quantum tunneling of the magnetization in Mn₁₂ac more than 15 years ago has inspired both physicists and chemists alike. This class of molecules, now called single-molecule magnets (SMMs), has very recently been expanded to heterometallic clusters incorporating transition metal and rare earth ions. The 4f ions were chosen because of their large angular momentum and magnetic anisotropy. Inelastic neutron scattering experiments were performed on the time-of-flight disk-chopper spectrometer IN5 at ILL on the SMM Mn₂Nd₂. A magnetic model was developed which perfectly describes all data, including the magnetic data. It was found that neither the large anisotropy nor the large angular momentum of the Nd^III ions is the main reason for the SMM behavior in this molecule. Our analysis of the data indicates that it is the weak coupling of the Nd^III ions to the Mn^III ions, usually considered as a drawback of rare earth ions, which enhances the relaxation time and therefore leads to SMM behavior.