Regensburg 2007 – scientific programme

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MA: Fachverband Magnetismus

MA 15: Poster:ThinFilms(1-33),Transp.(34-49),ExchBias(50-56),
Spindynamics(57-70),Micro-nanostr.Mat.(71-82),
Particles/Clust.(83-88), Mag.Imag./Surface(89-96),
Spinelectronics(97-109), Theory/Micromag.(110-116),
Spinstruct/Phasetr.(117-128),Magn.Mat.(129-139),
Aniso.+Measuring(140-145), MolMag.(146-152),
MSMA(153-156)

MA 15.109: Poster

Tuesday, March 27, 2007, 15:00–19:00, Poster A

Magnetic tunnel transistor with epitaxial FeCo/Au/FeCo base — •Alexander Spitzer, Julien Vigroux, and Günther Bayreuther — Universität Regensburg, Institut für Experimentelle und Angewandte Physik, Regensburg

The magnetic tunnel transistor (MTT) is a promising candidate for a highly sensitive magnetic sensor. In the present MTT structure hot electrons are injected into a spin valve base from a metallic emitter across a tunnel barrier. They cause a ballistic current, I_C, across the Schottky barrier with the GaAs substrate as the collector. By epitaxial growth of the spin valve the transfer ratio of collector current I_C to emitter current I_E is expected to increase because of less structural defects [1]. We present MTTs with a fully epitaxial Fe₃₄Co₆₆/Au/Fe₃₄Co₆₆ spin valve base grown on a n-GaAs(001) substrate, capped with an Al₂O₃ tunnel barrier and a Ta emitter. The samples are characterized by STM, XPS, TEM and temperature dependent MOKE. For electron energies above 0.8 eV a clear magnetic field-dependent ballistic current is measured in the collector. The temperature dependence of the magneto-current ratio (MCR), i.e. normalized difference of I_C between parallel and antiparallel alignment of both FeCo layers, is discussed.

[1] T. Hagler, C. Bilzer, M. Dumm, W. Kipferl, G. Bayreuther, J. Appl. Phys. 97, 10D505 (2005)