Regensburg 2007 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 29: Magnetic Measuring Methods / Sensors / Actuators
MA 29.3: Vortrag
Donnerstag, 29. März 2007, 15:45–16:00, H5
A novel method for a measurement of magneto-optical effects in thin self-supporting foils — •T. Weber, H. Backe, W. Lauth, P. Kunz, and A. Sharafutdinov — Institut für Kernphysik, Universität Mainz, Germany
A novel interferometric method for the measurement of the magneto optical rotation (MOR) of rare earth elements and 3d transition metals as Fe, Co, Ni was developed at Mainzer Mikrotron MAMI. The strong absorption lines resulting from allowed dipole transitions between the 2p3/2 (2p1/2) core states and empty 3d valence states are accompanied by a strong X-ray magnetic circular dichroism (XMCD) effect wich can be used to probe the magnetic properties of materials. The experiment arrangement consists of two collinear undulators and a grating spectrometer. The second undulator can be both, moved along and also be rotated around the electron beam axis. A magnetized foil placed between the undulators causes a phase shift and an attenuation of the oscillation amplitude. Due to the XMCD and MOR effect the coherent linear polarized light from the first undulator suffers a helicity dependent rotation and absorption resulting in elliptical polarized light. The second undulator acts as an analyzer, and no additional polarization state analyzer is required. The method has been validated by a measurement of Δδ(ω) and Δβ(ω) of the complex index of refraction n±=(δ0±Δδ)+i (β0±Δβ) at the L2,3-absorption edges of nickel. This work has been supported by DFG under contract BA 1336/1-3.