Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 27: Spin Electronics / Spininjection in Heterostructures
MA 27.2: Vortrag
Mittwoch, 25. März 2009, 17:00–17:15, HSZ 103
Optimized spin-injection and detection in lateral all-metal spin-valve devices with integrated tunnel barriers — •Andreas Vogel, Jeannette Wulfhorst, and Guido Meier — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg
Injection, manipulation, and detection of spin-polarized currents are fundamental issues in spintronics. We study the spin-dependent transport in lateral all-metal spin-valve devices with different tunnel barriers at the interface between the ferromagnetic electrodes (Ni80Fe20) and the interconnecting metal strip (Al or Cu). A tunnel barrier can enlarge the spin polarization of the injected current [1-3]. Different total conductivities per cross-sectional area ΣC of the aluminum oxide tunnel barriers are achieved by varying the oxygen pressure, the oxidation time, and the thickness of the naturally oxidized Al film. The spin-dependent transport in nonlocal geometry is described theoretically [3]. Transport measurements at temperatures of liquid helium are performed and compared to the theoretical description. A nonlinear increase of the spin polarization in the normal metal is observed for a decreasing tunnel conductance ΣC. We experimentally verify a saturating behavior for lower ΣC.
[1] F. J. Jedema et al., Nature 416, 713 (2002)
[2] S. O. Valenzuela et al., Appl. Phys. Lett. 85, 5914 (2004)
[3] A. van Staa, J. Wulfhorst, A. Vogel, U. Merkt, and G. Meier,
Phys. Rev. B 77, 214416 (2008)