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MA: Magnetismus

MA 13: Spinabh
ängiger Transport I

MA 13.5: Talk

Saturday, March 5, 2005, 11:45–12:00, TU EMH225

Spin-polarized tunneling in Fe/X/MgO/Fe (X=V,Cr) — •Jussi Enkovaara, Daniel Wortmann, and Stefan Blügel — Forschungszentrum Jülich, Institut für Festkörperforschung, 52425 Jülich

We present first-principles calculations on Fe/X/MgO/Fe system where the X element is V or Cr. Fe/MgO/Fe is a prototype system for tunneling magnetoresistance (TMR). Previous experimental and theoretical investigations have reported large magnetoresistance in epitaxial junctions. By adding layers of V or Cr on the one side of the junction, we can study the effect of interfacial electronic structure on the tunneling conductance.

The calculations are done within the density-functional theory with the full-potential linearized augmented plane wave (FLAPW) method. The novel embedded Green function method enables us to treat semi-infinite junctions and to calculate the ballistic conductance within the Landauer formalism. The results show large changes in the conductance already when one layer of V or Cr is inserted in the system. These findings can be interpreted in terms of the symmetry of the contributing electronic states.