Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 10: FV-internes Symposium "Molecular Magnetism" (Organizer: H.J. Krüger)
MA 10.4: Hauptvortrag
Samstag, 5. März 2005, 10:30–11:00, TU H1012
Frequency Domain Magnetic Resonance Spectroscopy on Molecular Magnets — •Joris van Slageren1, Nadeschda Kirchner1, Suriyakan Vongtragool1, Marc Duran1, Fadi El Hallak1, Alexander Mukhin2, Boris Gorshunov2, and Martin Dressel1 — 11. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart — 2General Physics Institute, Russian Academy of Sciences, Moscow, Russia
One of the most important parameters determining the properties of molecular magnets is the magnetic anisotropy in the form of zero-field splitting of the ground spin state. This parameter determines the energy barrier and therefore the slow magnetization relaxation dynamics. We have shown over the past years that frequency domain magnetic resonance spectroscopy (FDMRS) is excellently suited to the determination of zero-field splittings. Among its merits are: the lack of necessity of an external magnetic field, and easy access to very large zero-field splittings. Several pertinent examples will be shown. The magnetic resonance lineshapes give information on distributions in the sample as well as excited spin state dynamics. Because frequency and magnetic field are independent experimental parameters in the FDMRS technique, more sophisticated experiments can be performed. For example, we have spectroscopically studied the relaxation of the magnetization. We have demonstrated significant differences in line positions and line shapes between nonmagnetized and magnetized single molecule magnet samples. Finally, we will also show that single molecule magnets can function as tunable radiation polarization rotators in the THz range.