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MA: Magnetismus

MA 25: Spinabh
ängige Transportph
änomene I

MA 25.10: Vortrag

Donnerstag, 27. März 2003, 17:30–17:45, HSZ/04

Effect of the interface properties on the magneto-resistance of planar Fe/MgO/Fe tunnel junctions — •Arthur Ernst¹, Jürgen Henk¹, Mohammed Bouhassoune¹, Patrick Bruno¹, Markus Däne², Diemo Ködderitzsch², and Wolfram Hergert² — ¹MPI für Mikrostrukturphysik, Halle (Saale) — ²Martin-Luther-Universität Halle-Wittenberg, Halle (Saale)

Spin-dependent scattering at interfaces determines the magneto-resistance of small spintronic devices to a high degree. Planar tunnel junctions of Fe/MgO/Fe lend themselves support for a theoretical investigation of interface properties: Recent experiments found an FeO layer at the interfaces [1], instead of the ‘cut & paste’ geometry assumed in previous theoretical work.

To investigate the effect of the interface properties, in particular of the FeO layer, we performed ab-initio KKR calculations for the electronic and magnetic structures as well as for the ballistic tunnel conductance. The self-interaction correction was applied for the localized 3d-electrons in the FeO layer.

For tunnel junctions with several MgO-spacer thicknesses we find significant changes of the electronic and magnetic properties with composition of the interface layers. These changes are reflected in the wavevector-resolved conductance and, hence, in the tunnel magneto-resistance.

[1] H. L. Meyerheim, R. Popescu, J. Kirschner, N. Jedrecy, M. Sauvage-Simkin, B. Heinrich, and R. Pinchaux, Phys. Rev. Lett. 87 (2001) 076102.