Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 37: Spin Dependent Transport Phenomena
MA 37.4: Vortrag
Donnerstag, 26. März 2009, 16:00–16:15, HSZ 403
ZnO-based magnetic tunnel junctions — •Shengqiang Zhou1, Qingyu Xu2, L. Hartmann3, A. Muecklich1, M. Helm1, G. Biehne3, H. Hochmuth3, M. Lorenz3, M. Grundmann3, and H. Schmidt1 — 1Forschungszentrum Dresden-Rossendorf, Bautzner Landstraße 128, 01328 Dresden — 2Southeastern University, Nanjing 211189, China — 3Universität Leipzig, Linnéstraße 5, 04103 Leipzig
Spin-polarized tunnel magnetoresistance (TMR) effects occur when two ferromagnets are separated by a thin insulator. The resistance of the tunneling current changes with the relative magnetization orientation of the magnetic bottom and top electrode. The research is fuelled by the demanding of magnetoresistive random access memory (MRAM) devices. Novel MRAM cells are based on magnetic tunnel junctions with current-induced switching. It has been shown that semiconductors need a current pulse for switching which is two orders of magnitude smaller in comparison to metals [1]. In this talk, we report the clearly observed tunneling magnetoresistance at 5 K in magnetic tunnel junctions with Co-doped ZnO as the bottom electrode and Co as the top electrode prepared by pulsed laser deposition and thermal evaporation [2], respectively. Spin-polarized electrons were injected from Co-doped ZnO to the crystallized Al2O3 separation layer and tunnelled through the amorphous part of the Al2O3 barrier. Our studies demonstrate the spin polarization in Co-doped ZnO and its possible application in future ZnO-based spintronics devices. [1] M. Yamanouchi et al., Nature 428, 539 (2004). [2] Q. Xu et al., Phys. Rev. Lett. 101, 076601 (2008).