Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 6: Magnetic nanoparticles (joint session MA/CPP)

CPP 6.10: Vortrag

Montag, 12. März 2018, 12:00–12:15, H 0112

Magnetic properties of shell-ferromagnetic precipitates in decomposed off-stoichiometric Ni-Mn-based Heusler alloys, studied by ferromagnetic resonance (FMR) — •F. Scheibel^1,3, D. Spoddig¹, R. Meckenstock¹, T. Gottschall^2,3, M. Fries³, A. Çakir⁴, M. Farle¹, O. Gutfleisch³, and M. Acet¹ — ¹Faculty of Physics and CENIDE, University Duisburg-Essen, 47057 Duisburg, Germany — ²High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, Germany — ³Institut für Materialwissenschaft FG Funktionale Materialien, Technische Universität Darmstadt, 64289 Darmstadt, Germany — ⁴Department of Metallurgical and Materials Engineering, Muğla Sitki Koçman University, 48000 Muģla, Turkey

Off-stoichiometric Ni₅₀Mn_25−yX_y (25>y>0) Heusler alloys decompose into ferromagnetic (FM) Ni₅₀Mn₂₅X₂₅ and antiferromagnetic Ni₅₀Mn₅₀ components when annealed between 600 and 750 K [1]. In the case of y=5 annealed at 650 K, shell-ferromagnetic Ni₅₀Mn₂₅X₂₅ nano-precipitates of about 3 nm are formed. High-field FMR measurements up to 12 T verify the existence of a strong coupling of the shell of the precipitates with the surrounding Ni₅₀Mn₅₀ matrix [2]. Magnetization measurements show a rotation of the shell-spins first above 5 T, while the core shows a soft FM behavior. The magnetic hysteresis is vertically shifted, which makes this material interesting for magnetic-field proof permanent memory application. Work supported by the Deutsche Forschungsgemeinschaft (SPP 1599).
A. Çakir et al., Sci. Rep. 6 , 28931 (2016)
F. Scheibel et al., AIP Adv. 7, 056425 (2017)