Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 5: Micro- and Nanostructured Magnetic Materials I
MA 5.1: Vortrag
Montag, 22. März 2010, 11:00–11:15, H23
Microresonator setup for Ferromagnetic Resonance investigations of nanoobjects — •Anja Banholzer1, Ryszard Narkowicz2, Dieter Suter2, Ralf Meckenstock1, Jürgen Lindner1, and Michael Farle1 — 1Fakultät für Physik and Center for Nanointegration Duisburg-Essen, Universität Duisburg-Essen, 47048 Duisburg, Germany — 2Institut für Physik, Universität Dortmund, 44227 Dortmund, Germany
For Ferromagnetic Resonance (FMR) experiments a minimum number of spins on the order of 1012 (e.g. for Permalloy) are necessary. To enhance the sensitivity of the FMR detection, we have designed a microresonator setup with very high sensitivity, which allows for investigating small nanoobjects, for which conventional FMR detection would fail. The microresonators are prepared using Electron Beam Lithography. The constant microwave field is generated within the resonator at the position of the sample. Due to the resonator geometry, the resonance frequency for our measurements is fixed at 14 GHz. To observe the FMR, we sweep the externally applied magnetic field. With the microresonator we show the detection of a single Permalloy stripe with the size of 5 µ m x 0.5 µ m x 0.05 µ m. The measured spectra are in good agreement with theoretical calculations. We achieve a sensitivity of 4 · 106 spins/(G · √Hz). To demonstrate the flexibility of the approach, FMR measurements are performed on an epitaxial iron disc containing about 1010 spins. Financial support by DFG and SFB 491 is acknowledged.