Hamburg 2001 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

AM: Magnetismus

AM 9: Poster: Magnetowid. (1-17), Dü. Schichten (18-34), Oberfl
ächenmag. (35,36), Mikr. Methoden (37-45), Mikromag. (46-58), Phasenüberg. (59-77), Spektroskop. (78-91), Nanokr.Mat.(92-96), Anisotrop. (97-101), Schmelzen(102-104),Sonst/postdeadl.(105-109)

AM 9.3: Poster

Tuesday, March 27, 2001, 14:45–19:00, Foyer S 3

Dependence of magneto-current of a spinvalve transistor on collector bias voltage. — •Yuji Fujiwara^1,2, Mutsuko Jimbo³, and Günther Bayreuther² — ¹Department of Physics Engineering, Mie University, Kamihama 1515, Tsu 514-8507, Japan — ²Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany — ³Department of Electrical Engineering, Daido Institute of Technology, Nagoya 457-8351, Japan

A spinvalve transistor (SVT) has been proposed by Monsma et al. as a new current-perpendicular-to-the-plane (CPP) giant magnetoresistance (GMR) device. Mizushima et al. proposed a different type of SVT which had an AlO_x tunneling barrier between emitter and base. In both cases, electrons are injected only from the emitter electrode. In the present experiments, an AlO_x layer is used as emitter barrier. The electrons are injected from the emitter and the collector electrodes in order to investigate the behavior of electrons moving in opposite directions in the SVT. Samples were prepared by magnetron sputtering. Patterning was done by lift-off and etching techniques. The sample structure was Si / GMR layer / AlO_x / emitter electrode. The collector current changes its sign depending on the collector bias voltage. When a magnetic field is applied to the film, electrons travelling from the emitter to the collector and from the collector to the emitter show spin dependent scattering. For the collector bias voltage where the two electron currents are almost in balance, a large ratio of collector current change of about 1000% was obtained at room temperature. Some results for patterned samples will be presented.