Dresden 2003 – wissenschaftliches Programm
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MA: Magnetismus
MA 30: Spinabh
ängige Transportph
änomene II
MA 30.7: Vortrag
Freitag, 28. März 2003, 12:15–12:30, HSZ/401
LOW-FIELD TRANSVERSE MAGNETOVOLTAGE in MANGANITE FILMS — •Vasily Moshnyaga1, Sigrun A. Koester1, Bernd Damaschke1, Reinhard Tidecks2, and Konrad Samwer1 — 1I. Pyhsikalisches Institut, Universitaet Goettingen, Bunsenstrasse 9, 37073 Goettingen — 2Institut fuer Physik, Universitaet Augsburg, Universitaetstrasse 1, 86159 Augsburg
The temperature and in plane magnetic field dependence of the transverse voltage, Vy, were studied in patterned epitaxial films of La0.7Ca0.3MnO3/MgO (LCMO) with Tc=270 K and La0.7(Ca,Sr)0.3MnO3/MgO (LSCMO, Tc=310 K). In the paramagnetic region the Vy(T) shows an insulating behavior similar to that of the longitudinal voltage (resistance). With the onset of long range ferromagnetic order near Tc an additional contribution to Vy appears, exhibiting a sin(2alpha)- dependence on the angle "alphaNo-dq between the current and the magnetic field, H. Vy is very sensitive to low fields and shows a hysteretic behavior due to magnetization reversal. For example, LSCMO film exhibit room temperature sensitivity 20 %/Oe and magnetovoltage, Vy(H)/Yy(0)=220 % for H≈Hc=10-20 Oe. The transverse voltage is originated from an anisotropic magnetoresistance (AMR) effect and is closely related to the magnetization state of films. The results show a potential for planar device applications as field sensing and memory elements. Support by the DFG via SFB602, TPA2 is acknowledged.