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 18.26: Poster

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

Training and temperature effects of epitaxial and polycrystalline Ni₈₀Fe₂₀/Fe₅₀Mn₅₀ exchange biased bilayers — •Marian Fecioru-Morariu¹, Jerzy Wrona², Cristian Papusoi³, and Gernot Güntherodt¹ — ¹Physikalisches Institut (IIA), RWTH Aachen University, 52056 Aachen, Germany — ²AGH University of Science and Technology, 30-059 Krakow, Poland — ³SPINTEC, CEA/CNRS, 38054 Grenoble Cedex 9, France

For exchange biased bilayers of Ni₈₀Fe₂₀/Fe₅₀Mn₅₀, the effects of crystalline structure on the training effect of the exchange bias field (H_EB) and of the coercive field (H_C) have been investigated for (001) and (110) epitaxial as well as polycrystalline thin film samples [1]. The training effect of H_EB and H_C at 5 K is strongest for the polycrystalline sample as compared to the (110)-oriented sample. The training effect is found to originate from the hysteresis cycle-number dependence of H₁, the switching field of the descending branch of the hysteresis loop. A very good qualitative agreement is observed between the cycle-number dependence of H_EB and of the fraction of uncompensated spins of the AFM. In the temperature range between 5 K and 300 K, H_EB and H_C are found to depend strongly on the crystalline structure and orientation of the FM/AFM bilayers. // The financial support through the EU Research Training Network NEXBIAS (HPRN-CT-2002-00296) is gratefully acknowledged. [1] M. Fecioru-Morariu, et al., submitted.