Regensburg 2007 – wissenschaftliches Programm
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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 15.38: Poster
Dienstag, 27. März 2007, 15:00–19:00, Poster A
Temperature dependence of current induced domain wall motion in NiFe — •Markus Laufenberg, Wolfgang Bührer, Pascal Dagras, Pierre-Eric Melchy, Mathias Kläui, Lutz Heyne, Dirk Backes, Daniel Bedau, and Ulrich Rüdiger — Universität Konstanz, 78457 Konstanz
Recently reversal by current-induced domain wall motion (CIDM) has become the focus of intense research [1], but quantitative agreement between experiment and theory is often poor. Since so far theory does not consider temperature whereas experiments are often carried out at room temperature, that might be one reason for the observed discrepancies.
In this work we present an experimental study of domain wall motion induced by current pulses as well as by conventional magnetic fields at temperatures between 2 and 300 K in Ni80Fe20 rings. The rings are contacted by gold pads to allow for current injection and magnetoresistance measurements. Via the AMR-effect a change in the magnetic configuration can be detected.
Whereas field-induced domain wall motion is a thermally activated process it turns out that CIDM at higher temperatures is less effective than at lower temperatures [2]. The effect of Joule heating due to the current pulses is measured and taken into account to obtain critical fields and current densities at constant sample temperatures. This allows for a comparison of our results with theory.
[1] M. Kläui, et.al., Phys. Rev. Lett. 94, 106601 (2005).
[2] M. Laufenberg, et.al., Phys. Rev. Lett. 97, 046602 (2006).