Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 20: Micro- and Nanostructured Magnetic Materials I
MA 20.1: Vortrag
Mittwoch, 25. März 2009, 12:45–13:00, HSZ 403
Magnetization reversal of single submicron NiFe rectangles — •Hendrik Spahr, André Kobs, Daniel Stickler, Sebastian Hankemeier, and Hans Peter Oepen — Institut für Angewandte Physik, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg, Germany
The magnetization reversal of single submicron NiFe rectangles with aspect ratio of two has been investigated by means of magnetotransport measurements using anisotropic magnetoresistance (AMR). The structures have been carved into a Cr(10nm)/NiFe(20nm) double layer utilizing a highly focused ion beam (FIB). The material surrounding the rectangles has been rendered paramagnetic by applying an ion dose of 6000 µC/cm2, which destroys ferromagnetism without decreasing the electric conductivity much. To perform in situ two-point MR measurements the structures have been contacted via a tungsten tip attached to a micromanipulator [1]. To investigate the hard- and easy-axis hysteresis loops, measurements have been performed with varying orientation of magnetic field with respect to current and main axis of the rectangles. The magnetization behaviour of the rectangles is mainly determined by the uniaxial shape anisotropy. The shape anisotropy constant can be estimated from the hard axis loops. The state in remanence of the rectangles has been investigated via scanning electron microscopy with polarization analysis (SEMPA).
[1] Daniel Stickler et al., Rev. Sci. Instr. 79, 103901 (2008)