Dresden 2017 – wissenschaftliches Programm
MA 37.4: Vortrag
Mittwoch, 22. März 2017, 10:15–10:30, HSZ 401
Dimension and shape dependence of magnetization reversal mechanisms and magnetic anisotropies in four-fold nano-magnets — •Andrea Ehrmann1 and Tomasz Blachowicz2 — 1Bielefeld University of Applied Sciences, Faculty of Engineering and Mathematics, Bielefeld, Germany — 2Silesian University of Technology, Gliwice, Poland
Magnetic nanoparticles are intensively investigated due to their intriguing magnetic properties, such as a broad variety of magnetization reversal mechanisms and unusual anisotropies. Especially fourfold nanowire structures were shown to exhibit technologically interesting magnetic properties - they may show a step in the hysteresis loop correlated with a stable intermediate state at remanence which can be utilized in quaternary memory cells. Magnetization reversal mechanisms and the possible existence of such stable intermediate states, however, depend strongly on the materials, dimensions, and exact shapes of the nanoparticles under investigation.
In a recent project, fourfold nanoparticles of different dimensions and shape modifications were modeled using typical properties of permalloy, iron, and cobalt. In these systems, different numbers of stable intermediate states were found in different angular orientations. For cobalt, the largest number of steps was simulated, while coercive fields showed an irregular and unpredictable behavior.
In all cases, comparisons with previous calculations underlined that common mathematical descriptions of fourfold magnetic systems are no longer valid in the investigated nanoparticles.