|2024-02-07: Ausschreibung Doktorand*innen oder PostDoc Stelle
Wir haben die Stelle eines wissenschaftlichen Mitarbeitenden TVL 13 ausgeschrieben: https://www.uni-due.de/karriere/stelle.php?kennziffer=086-24 . Es können sich sowohl Personen, die an einer Promotion interessiert sind, als auch promovierte Personen bewerben, die entweder Ihr eigenes Projekt mitbringen und dieses durch eine(n) weiteren Mitarbeiter*in verstärken wollen, oder selber die PostDoc Position annehmen wollen. Die PostDoc Stelle könnte nach zwei Jahren nach positiver Evaluation um weitere zwei Jahre verlängert werden.
|2024-02-02: We welcome Emmanouil Kasotakis to our team!
|2024-01-18: "Cellular precipitation in Ni-Mn-Sn revealed", Phys. Rev. Materials 7 (2023) 124411
"Cellular precipitation in Ni-Mn-Sn revealed", Phys. Rev. Materials 7 (2023) 124411 Combining the expertise of 5 participating projects in the SFB/TRR 270 HoMMage the location and morphology of ferromagnetic precipitates in Ni-Mn-Sn was determined. Ni50Mn45Sn05 heated above 600 K decomposes into ferromagnetic Ni2MnSn precipitates in an antiferromagnetic NiMn matrix. If an external magnetic field is applied during annealing, magnetic hysteresis curves with high coercive fields of up to 5 T can be achieved. The origin of this hysteresis has been attributed to the coupling of the antiferromagnetic matrix L10 NiMn with ferromagnetic precipitates (Sn enriched regions), whose location and morphology were not known. To close this knowledge gap, a range of sophisticated experimental techniques – ranging from magnetic force microscopy over transmission electron microscopy to atom probe tomography -was applied aside from conventional magnetometry and x-ray diffraction. The decomposition type is identified as a cellular precipitation starting at grain boundaries and growing into the grains. This leads to a multilayer thin film like lamellar structure with a lamella thickness in the nm range as seen in the attached figure. These results may provide a basis for understanding the magnetic interactions, which lead to the magnetic hysteresis with ultra high coercivity in these types of "shell ferromagnets"
Abb: a) HAADF STEM image of the sample annealed for 24 h at 700 K. The decomposition product of phase I toward Ni2MnSn and NiMn is visible and forms a lamellar structure.
(b) HAADF STEM image of the region marked in (a) (yellow rectangle). The thickness of the Ni2MnSn lamellar precipitates is around 10 nm.
(c) EDX mappings of Ni, Mn, and Sn performed on the area shown in (b).
(d) EDX linescans measured within the yellow rectangles shown in (b). The x-axes of the plots of the linescans follow the yellow arrows.
|2023-08-12: Pinned magnetic moments in the collinear antiferromagnet PdMn
|2023-08-09: Helical magnetic structure of epitaxial films of nano-laminated Mn2GaC MAX phase
|2023-07-18: Femtosecond Laser Ablation-Induced Magnetic Phase Transformations in FeRh
|2023-07-18: Easy up-scalable synthesis for ferrite nanoparticles
|2023-06-29: Ni-Mn-Sn Heusler alloys manufactured by e-beam and laser powder bed fusion
|2023-06-16: Good Bye Manolis!
After his 5-months ERASMUS-funded internship Emmanouil Kasotakis left us after setting up and testing a now fully functioning sputter deposition system which he commissioned together with Moritz Vanselow and Dr. Anna Semisalova.
We wish him a fruitful and successful career wherever his interest my lead him.
|2023-06-13: Towards THz Physics with GHz excitation (inertia in spin dynamics)
The dynamics of magnetic moments consists of a precession around the magnetic field direction and a relaxation towards the field to minimize the energy. While the magnetic moment and the angular momentum are conventionally assumed to be parallel to each other, at ultrafast time scales their directions become separated due to inertial effects. The inertial dynamics gives rise to additional high-frequency modes in the excitation spectrum of magnetic materials. Here, our international collaboration reviews the recent theoretical and experimental advances in this emerging topic and discuss the open challenges and opportunities in the detection and the potential applications of inertial spin dynamics.
For further details see https://doi.org/10.1016/j.jmmm.2023.170830.
|2023-05-02: We welcome Berna Gündogdu Gültepe!