Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)

MA 14.47: Poster

Dienstag, 25. März 2003, 15:15–19:15, Zelt

Injection of ballistic Electrons into Semiconductors — •Jan Bornemeier, Hubert Brueckl, and Guenter Reiss — University of Bielefeld, Department of Physics, Universitaetsstr.25, 33615 Bielefeld

Magnetic Tunnel Junctions (4-10nm Co/1,8nm Al₂O₃/20nm Py) were used to inject ballistic electrons into Zn-doped GaAs (100) substrates. The TMR elements have an area resistance of 5 MΩµm² and have been patterned with scanning laser lithography to a lateral size of 100 x 100 µm². The Schottky barrier height between the lower electrode and the semiconductor is 0.5eV with an ideality factor of 2.3. The current via this Schottky barrier changes with the magnetization of the magnetic layers. The dependence of this ballistic current on the magnetic field, the bias voltage at the tunnel barrier and the temperature is investigated. A ballistic magneto current can be seen at temperatures lower than 250K and bias voltages above 400mV. At 25K and 700mV, the TMR ratio is 2%, the ballistic current changes 4%.