Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 18: Poster I : Bio Magn. (1-2); Mag.Imgaging (3-9); Magn. Semiconductors (10-16); Half Metals & Oxides (17-20); Coupl.Phenomena (21-27); Magn. Mat. (28-41); Micro & Nanostr. Magn. Materials (42-61); Micro Magn. (62-64); Surface Magnetism (65-70); Transport Phenomena (71-85)

MA 18.53: Poster

Dienstag, 26. Februar 2008, 15:15–18:30, Poster E

Magneto-optic investigations on the dynamics of the switching behavior of CoFeB TMR structures — •Georg Wolf, Patrizio Candeloro, Patricia Martin Pimentel, Helmut Schultheiss, Britta Leven, and Burkard Hillebrands — FB Physik and FSP MINAS, TU Kaiserslautern, Erwin-Schrödinger-Str. 56, 67663 Kaiserslautern, Germany

For technical applications of TMR structures like magnetic random access memory or magnetic logic devices the dynamics of the switching behavior is of great importance. Optimizing the switching process is a major task in the development of these devices. We report on time-resolved Kerr microscopy investigations on the dynamics of 3 x 6 µm² ellipsoidal CoFeB-TMR structures under the influence of two orthogonal magnetic field pulses [1]. The TMR stack has been prepared in collaboration with the group of Guenter Reiss, University of Bielefeld. This study is focused on the dynamic behavior of the free magnetic layer. The field pulses were oriented in 45^∘ geometry with respect to the easy magnetic axis of the system in the so called Savtchenko-geometry [2]. The field response of the different magnetization components is presented and compared with simulations in a macro spin approximation. These simulations yield a good agreement with the measurements. Financial support by the EU-IST Project MAGLOG (510993) is gratefully acknowledged.

[1] P.Martin Pimentel et al, Appl. Phys. Lett., 88, 122510, (2006).

[2] L. Savtchenko et al. US Patent 6,545,906 B1, Apr. 8 (2003).