Regensburg 2022 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Bulk Materials: Soft and Hard Permanent Magnets

MA 32.2: Vortrag

Donnerstag, 8. September 2022, 15:15–15:30, H43

Magnetic-field-, temperature- and time-dependence of structural and magnetic properties of shell-ferromagnets — Nicolas Josten¹, Steffen Franzka², Mehmet Acet¹, Franziska Scheibel³, Asli Çakir⁴, Franziska Staab⁵, and •Michael Farle¹ — ¹Faculty of Physics and Center for Nanointegration (CENIDE), University Duisburg Essen, Duisburg, 47057, Germany — ²Interdisciplinary Center for Analytics on the Nanoscale (ICAN), Carl-Benz-Straße 199, 47057 Duisburg, Germany — ³Functional Materials, Institute of Materials Science, Technical University of Darmstadt, Alarich-Weiss-Str. 16, 64287 Darmstadt, Germany — ⁴Department of Metallurgical and Materials Engineering, Mugla University, 48000 Mugla, Turkey — ⁵Physical Metallurgy, Institute of Materials Science, Technical University of Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt, Germany

The strong pinning of magnetic moments in off-stoichometric Ni₅₀Mn₄₅X₀₅ (X= Al, Ga, In, Sn, Sb) Heusler alloys after magnetic annealing at 650K is known as the shell-ferromagnetic effect. This pinning leads to coercive fields larger than 6 Tesla and is interesting for the development of novel ultrahard permanent magnets. We report on the optimization of the strength of this effect by varying the annealing field, time, and temperature. The origin of the effect is discussed based on these results combined with magnetic force microscopy images.

Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) * Project-ID 405553726 * TRR 270.