Berlin 2005 – wissenschaftliches Programm

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MA: Magnetismus

MA 15: Magnetische Kopplungsph
änomene / Exchange Bias

MA 15.3: Vortrag

Samstag, 5. März 2005, 14:30–14:45, TU H1028

Controlling orbital occupation and spin orientation in CoO layers bystrain — •M. W. Haverkort¹, S. I. Csiszar², Z. Hu¹, A. Tanaka³, H. H. Hsieh⁴, H.-J. Lin⁵, C. T. Chen⁵, T. Hibma² und L. H. Tjeng¹ — ¹II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany — ²Materials Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands — ³Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima 739-8530, Japan — ⁴Chung Cheng Institute of Technology, National Defense University, Taoyuan 335, Taiwan — ⁵National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu 30077, Taiwan

We have observed that CoO films grown on different substrates show dramatic differences in their magnetic properties. Using polarization dependent x-ray absorption spectroscopy at the Co L_2,3 edges, we revealed that the magnitude and orientation of the magnetic moments strongly depend on the strain in the films induced by the substrate. We presented a quantitative model to explain how strain together with the spin-orbit interaction determine the 3d orbital occupation, the magnetic anisotropy, as well as the spin and orbital contributions to the magnetic moments. Control over the sign and direction of the strain may therefore open new opportunities for applications in the field of exchange bias in multilayered magnetic films.