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MA: Fachverband Magnetismus
MA 41: Micromagnetism / Computational Magnetics
MA 41.6: Vortrag
Mittwoch, 22. März 2017, 16:30–16:45, HSZ 101
Shell-ferromagnetism of nano-precipitate in a Ni-Mn-In off-stoichiometric Heusler alloy by ferromagnetic resonance — •Franziska Scheibel1, Detlef Spoddig1, Ralf Meckenstock1, Asli Çakir2, Michael Farle1, and Mehmet Acet1 — 1Faculty of Physics and CENIDE, University Duisburg-Essen, 47057 Duisburg, Germany — 2Department of Metallurgical and Materials Engineering, Muğla Sitki Koçman University, 48000 Muģla, Turkey
Previous studies have shown that the off-stoichiometric Ni-Mn-based Heusler alloys decompose into a ferromagnetic (FM) Ni50Mn25X25 Heusler alloy and the antiferromagnetic Ni50Mn50 alloy during temper-annealing [1]. Annealing of Ni50Mn45.1In4.9 in a field of 5 T leads to an alignment of the magnetic moments at the interface of the nano-precipitates along the field direction, leading to a vertical shift of the magnetic hysteresis which is stable up to 9 T and 500 K. The hard magnetic shell can only be reversed in a field of 12 T, which makes this material interesting for permanent magnetic memory application. We studied the coupling mechanism and interface exchange energy by ferromagnetic resonance (FMR). Bidirectional FMR measurements in the range −1.1 ≤ µ0H ≤ 1.1 T at 400 K show a corresponding signal to the decomposed FM phase, indicating a shape anisotropy. FMR studies up to 12 T shows that the FMR of the hard magnetic shell appears at the same resonance field as the FMR of the soft magnetic core but is only present after saturation at 12 T. Work supported by the Deutsche Forschungsgemeinschaft (SPP 1599).
A. Çakir et al., Sci. Rep. 6 , 28931 (2016)