|Koordinator des Seminars:
Prof. Dr. Hans-Joachim Elmers
Institut für Physik, KOMET 335
Institut für Physik
Donnerstag, den 24.08.2017
um 11:30 Uhr s.t. im ComZone, Staudinger Weg 7, 1. Stock
Michael Schöbitz, University of Sheffield
Domain wall (DW) dynamics, especially in artificially notched nanowires, are stochastic, resulting in detrimental effects on the reliability of ferromagnetic nanodevices proposed for memory and logic gate applications. We investigate the effect of nanowire geometry on the DW pinning probability (P(DWp)) and propose a method to measure the effect of temperature on P(DWp). In applications, variations in nanowire geometry and, more commonly, temperature are possible, however, the implications of these in regard to P(DWp) are not yet fully understood. Notched permalloy nanowires are fabricated using electron beam lithography with thermal evaporation and magnetisation reversals are characterised using a focussed magneto-optical Kerr effect magnetometer or by measuring the anisotropic magnetoresistance (AMR) effect. P(DWp) increases with increasing notch size, confirming previous findings. Pinning probability also increases with nanowire volume which is shown to be related by the Néel-Brown relaxation law. Probabilistic DW pinning is successfully measured using the AMR effect at room temperature, providing the foundation for a future study investigating the effect of temperature on P(DWp).