Herzlich willkommen bei der Arbeitsgruppe Farle

AG Farle

Struktur und Magnetismus nanoskaliger Systeme

Willkommen !

Wir begrüßen Sie sehr herzlich auf den Webseiten der Arbeitsgruppe Farle.
Das Verständnis magnetischer Eigenschaften von nanostrukturierten Materialien ist unsere Herausforderung !

Mehr über die Arbeitsgruppe erfahren ...

Forschung

zum TRR270

zu MaNaCa
zum MaNaCa Video

zu Magnetic Landscapes

zu ICAN

zu CENIDE

zu Online Videos of our Research

News

Nur deutschsprachig

Nur englischsprachig

alle

2024-04-26: "Magnete als Klimaretter" UNIKATE 60 Heft erschienen (April 2024)
Magnetische Materialien sind in allen Bereichen unseres täglichen Lebens – vom Kühlschrank, über Elektromotoren und Generatoren bis hin zu Sensoren und Spin basierter Informationsverarbeitung - zu finden. Im Rahmen der Forschungsaktivitäten des CRC/TRR 270 - Hysteresis design of magnetic materials for efficient energy conversion (HoMMage) haben die beteiligten Forscher*innen der Universität Duisburg-Essen eine allgemein verständliche, projektbezogene Beschreibung geliefert, warum Magnete "als Klimaretter" für unsere Zukunft wichtig sind. Das rund 100 Seiten umfassende Heft bietet eine hochaktuelle und unterhaltsame Lektüre und sollte zu weiteren Diskussionen mit Freunden, Familie und Bekannten anregen. Es ist unter folgendem Link als PDF zu erhalten: https://duepublico2.uni-due.de/receive/duepublico_mods_00081818.

2024-04-25: New PhD candidate in our group!

We congratulate our colleague Elisavet Papadopoulou to her successful M.Sc. defense. Her thesis has the title "Structure and magnetic properties of novel ferromagnetic CoFeMnNiInx (x=0; 10; 20; 30 at. %) High Εntropy Αlloys prepared by High Εnergy Βall Μilling".
We are very happy, that she will continue her work as PhD candidate in our group, working under the project A04 "Towards rare earth free permanent magnets by nanoscale phase decomposition" within CRC/TRR 270 HoMMage!
We wish a success in her research and excellent results!

2024-04-17: Visit of Dr. Natalia Shkodich to the TU Darmstadt

Dr. Natalia Shkodich was happy to visit Functional Materials group of Prof. Oliver Gutfleisch at the TU Darmstadt. For three days together with Dr. Franziska Scheibel and Dr. Alex Aubert she synthesized samples using SPS, performed magnetic characterization in the PPMS (14T) and studied phase transitions using DSC. The exchange took place in the framework of the SFB/TRR-270, subproject A04 (PIs Prof. Michael Farle and Dr. Natalia Shkodich) research on shell ferromagnetic materials to tune the magnetic hysteresis by nanoscale selective phase decomposition.

2024-03-25: DPG 2024 Berlin: Invited talk on magnetization inertia effects in spin dynamics
Our group actively participated at DPG Spring meeting 2024 in Berlin. Tatiana Smoliarova, Ivan Tarasov, Ulf Wiedwald, Jonas Wiemeler, Elisavet Papadopoulou presented their contributions, Inci Nur Sahin was elected for INNOMAG e.V. Prize 2024 Master Thesis contest. Anna Semisalova gave an invited talk on inertia effects in spin dynamics. Congratulations!

2024-02-02: We welcome Emmanouil Kasotakis to our team!

He will work on his PhD thesis within the DFG project titled "Tailoring magnetism of High Entropy Alloys (HEA) by high energy ball milling".
His research will be focused on the development of innovative (soft or hard) magnetic HEA materials with chemical and mechanical robustness.
We wish him success in his research and excellent results!

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.

Einige Eindrücke ...