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 !

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Neuigkeiten

2020-03-10: Non-standing spin-waves in confined micrometer-sized ferromagnetic structures under uniform excitation
Editors Pick (!) Non-standing spin-waves in confined micrometer-sized ferromagnetic structures under uniform excitation Appl. Phys. Lett. 116, 072401 (2020); https://doi.org/10.1063/1.5139881 Santa Pile et al. A long effort within an international collaboration (U. Linz, Duisburg-Essen, Stanford) including partners from the CRC/TRR 270 broke new ground in element-specific magnetic imaging with picosecond temporal and few nanometer spatial resolution. A non-standing characteristic of directly imaged spin-waves in confined micrometer-sized ultrathin Permalloy (Ni80Fe20) structures is reported along with evidence of the possibility to alter the observed state by modifications to the sample geometry.

2020-03-10: Dynamic unidirectional anisotropy in cubic FeGe with antisymmetric spin-spin-coupling
Nicolas Josten, et al. Scientific Reports 10, 2861, (2020) DOI: 10.1038/s41598-020-59208-8 Successful collaboration with TU-Darmstadt within CRC/TRR 270. We studied bulk polycrystalline B20 FeGe samples prepared in Darmstadt and measured ferromagnetic resonance spectroscopy. As a result we discovered strong (dynamical) unidirectional anisotropy. Such anisotropy is not present in static magnetometry measurements. B20 FeGe exhibits inherent Dzyaloshinskii-Moriya interaction, resulting in a nonreciprocal spin-wave dispersion. By X-band ferromagnetic resonance spectroscopy at 276 K  1 K, near the Curie temperature, a distribution of resonance modes was observed in accordance with the cubic anisotropy of FeGe. This distribution exhibits a unidirectional anisotropy, i.e. shift of the resonance field under field inversion, of KUD = 960 J/m3  10 J/m3, previously unknown in bulk ferromagnets. Additionally, more than 25 small amplitude standing spin wave modes were observed inside a micron sized FeGe wedge, measured at 293 K  2 K. These modes also exhibit unidirectional anisotropy. This effect, only dynamically measurable and not detectable in static magnetometry measurements, may open new possibilities for directed spin transport in chiral magnetic systems.

2020-01-17: Highlighted Publication
The publication based on our long term collaboration with the group of Vernica Salgueirio (university of Vigo, Spain) Shaping iron oxide nanocrystals for magnetic separation applications has been selected to be a part of a themed collection International Year of the Periodic Table: As attractive as magnets applications for magnetic materials. This themed collection is the seventh, and final, in a series celebrating the International Year of the Periodic Table. As Attractive as Magnets Applications for Magnetic Materials features papers from across the Materials and Nano journal portfolio; Materials Horizons, Nanoscale Horizons, Nanoscale, Nanoscale Advances and Journal of Materials Chemistry A, B & C. The papers selected for this themed issue focus on the current hot trends in the field of magnetic materials.


2020-05-29: Doktorandenstellen

In unserer Arbeitsgruppe sind Doktorandenstellen zum nächstmäglichen Zeitpunkt zu folgenden Projekten zu besetzen:

B09: "Hierarchical structuring of magnetocaloric materials with nm resolution"



2019-11-26: Cooperate Research Center TRR 270 HoMMage
We celebrate the new Cooperate Research Center TRR 270 HoMMage "Hysteresis Design of Magnetic Materials for Efficient Energy Conversion".
Starting Jan 1st, 2020 we will design and develop magnetic materials for applications in electro mobility, robotics and energy converters over the first period till Dec. 31st , 2023. In our group we have three positions for Ph.D. students available on projects related to this programme (see separate announcements).


2019-09-26: Workshop SpinS-2019 gathers experts in nanomagnetism at the University of Duisburg-Essen

Next week, 2-4 October 2019, more than 40 experts in physics, chemistry and materials science from 12 countries meet in “Die Wolfsburg” Academy in Mülheim an der Ruhr/Duisburg to share their research results and discuss new concepts in nanomagnetism and its applications, like energy-efficient computing and magnetic refrigeration.

The Workshop program covers the most recent experimental and theoretical research developments related to spin phenomena in nanoscale systems as well as the design, properties and applications of magnetic nanomaterials. It includes several emergent technologies based on spin-orbit torques, ultrafast spin dynamics in THz frequency range, magnonics, magnetoacoustics as well as novel materials like shell-ferromagnets, MAX phases (including 2D MXenes), and nanohybrids for theranostics applications actively developed in the working group AG Farle. The SpinS-2019 provides an interdisciplinary platform for meeting the specialists in fabrication and imaging of 2D and 3D magnetic nanostructures, and experts working towards various application areas – from spin dynamics and magnetic memory to additive manufacturing and biomedicine.

The meeting is organized by Michael Farle, Katharina Ollefs and Anna Semisalova, with a technical support of Michael Vennemann and Sabina Grubba. Organizers highly appreciate the financial support of the Center for Nanointegration Duisburg-Essen (CENIDE).

SpinS-2019 website

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