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2026-06-30: Congratulations! Master of Science for Moritz Kster with highest grades!
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Moritz Kster successfully completed the physics MSc study program! In his thesis "Analysis of Spin Dynamics and Dimensionality in the layered Antiferromagnet MnPS#" he studied the spin dynamics and magnetic phase transitions in quasi-2D van der Waals MnPS3 crystals using broadband electron spin resonance (ESR) and antiferromagnetic resonance (AFMR). He found a remarkable temperature-dependent transition from 2D to 3D correlations. Pictures show the MnPS3 crystal tructure from different viewpoint (a-c). (d) shows a characteristic false color plot of the observed resonances as function of magnetic field and frequency.
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2026-06-28: ExtraSchicht 27.06.2026 at the Faculty of Physics
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AG Farle actively participated in the
ExtraSchicht event, when faculty doors were opened to the public. Michael Farle delivered a public lecture titled "Magnete als Klimaretter Materialien fr eine emissionsfreie Zukunft" (Magnets as Climate Protectors: Materials for an Emission-Free Future), highlighting the role of advanced magnetic materials in sustainable technologies as for example researched in the CRC270 "Hysteresis design of magnetic materials for efficient energy conversion".
The event featured nightly lab tours "Magnete fr die Energie von Morgen Magnets for Tomorrow's energy" (Michael Farle, Anna Semisalova), where visitors explored our experimental facilities for research on magnetic materials synthesis and high-frequency spin dynamics. One highlight of the evening was the live demonstration of a superconducting maglev train (sponsored by CRC270), designed and explained by Nicolas Josten, offering a striking showcase of future technologies and the potential of magnetic materials.
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2026-02-19: New CRC/TRR 270 HoMMage publication: High-temperature additive manufacturing of Nd-Fe-B by powder bed fusion
In this study, crack-free and dense near-net-shape parts were successfully produced via electron beam powder bed fusion (PBF-EB) using a stress-reducing spot melting strategy. Identical gas-atomized powder powder (68.7Fe-19.2Nd-1.7B-1.9Ti-2.5Co-4.3Zr-1.4Pr) was also processed by laser powder bed fusion (PBF-LB). While PBF-EB samples showed high density and mechanical integrity, the PBF-LB parts suffered from significant porosity and cracking despite preheating, indicating insufficient thermal stress management. Magnetic characterization revealed coercivities up to 9.3 kA/m (11.7 mT) and specific saturation magnetization values of 136 Am2/kg at 310 K for PBF-EB samples. In contrast, PBF-LB samples exhibited considerably higher but still low coercivity (127 kA/m; 0.16 T) compared to the powder state, attributed to oxidation, phase inhomogeneity, and structural discontinuities. PBF-EB samples remained largely unaffected by post-processing heat treatment up to
1050 °C, suggesting a stable near-equilibrium microstructure already formed during PBF processing. PBF-LB samples underwent a breakdown of the initial finely structured matrix, the emergence of soft magnetic α-Fe phases and consequently magnetic deterioration, highlighting the metastable nature of their as-built state. These findings emphasize that magnetic performance in AM of rare-earth (RE) lean Nd-Fe-B alloys is governed not only by thermal exposure but also by process-inherent solidification kinetics and oxidation sensitivity. By highlighting the critical importance of decoupling thermal effects and solidification dynamics in AM, a framework for future alloy and process design strategies aimed at achieving high-performance, binder-free permanent magnets is provided.
For details see here: High-temperature additive manufacturing of Nd-Fe-B by powder bed fusion | Progress in Additive Manufacturing | Springer Nature Link.
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2026-01-27: New publication in Acta Materialia: Direct observation of nanoscale pinning centers in Ce(Co0.8Cu0.2)5.4 permanent magnets
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We are pleased to announce our recent publication within the framework of CRC/TRR20. In this joint study, we investigate Ce(Co1-xCux)5 permanent magnets using a correlative approach combining transmission electron microscopy (TEM) and atom probe tomography (APT). The analysis reveals a nanoscale cellular structure formed by spinodal decomposition.
Cu-poor cylindrical cells (∼5-10 nm in diameter and ∼20 nm in length) exhibit a disordered CeCo5-type structure with a composition close to Ce(Co0.9Cu0.1)5.3. These cells are separated by Cu-rich boundaries ∼5 nm thick, characterized by a modified CeCo5 structure with Cu ordering on Co sites and a composition of Ce(Co0.7Cu0.3)5.0. Micromagnetic simulations show that intrinsic Cu concentration gradients of up to 12 at.% Cu per nanometer induce strong spatial variations in magnetocrystalline anisotropy and domain-wall energy, leading to effective domain-wall pinning and high coercivity.
Compared to Sm2Co17-type magnets, Ce(Co0.8Cu0.2)5.4 exhibits a finer-scale pinning mechanism with reduced structural and chemical contrast. The identification of nanoscale chemical segregation in this nearly single-phase system provides a microstructural explanation for the long-standing phenomenon of “giant intrinsic magnetic hardness” in SmCo5-xMx-type materials and highlights new pathways toward the design of rare-earth-lean permanent magnets through controlled nanoscale segregation.
Follow this link for more information: https://doi.org/10.1016/j.actamat.2026.121906.
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2026-01-16: New insights into vibrational properties of 2D Materials
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Scientists from Grenoble, Bordeaux and the University of Duisburg-Essen have unlocked fresh understanding of two-dimensional material that could shape tomorrow's high-performance devices. They have synthesized high-quality Ti3C2Cl2 MXenes, an atomically thin metal carbide with chlorine surface groups, and used cutting-edge techniques to peer deep into how its atoms vibrate and conduct heat.
How lattice vibrations, tiny quantum mechanical ripples called phonons, move through 2D crystals differ from well-explored 3D materials. These vibrations influence everything from thermal conductivity to electrical behavior, but until now, scientists have struggled to measure them accurately in MXenes because of stacking disorder and non-uniform surface terminations.
By carefully growing MXene sheets with uniform chlorine terminations, the team captured exceptionally clear vibrational “fingerprints” using polarized Raman spectroscopy and combined these measurements with theoretical calculations. This revealed how different vibrational modes behave and how they change with temperature giving an unprecedented picture of optical phonon behavior in this 2D material.
In parallel, precise measurements of specific heat and corresponding calculations exposed how MXenes' heat capacity responds to temperature, uncovering tell-tale signs of their two-dimensional character at very low temperatures which is often hidden in other materials.
Understanding and controlling phonons in MXenes is a key step toward designing faster electronics, better thermoelectric materials, and improved energy-storage systems. This work lays solid scientific groundwork for tuning thermal and vibrational properties in 2D materials, bringing next-generation technologies a step closer.
The authors acknowledge financial support of the Deutsche Forschungsgemeinschaft and the Agence Nationale de la Recherche in the bilateral ANR-DFG project.
Reference:
M. Riabov, M. Vanselow, A. Champagne, et al. Phonon properties of 2D Ti3C2Cl2 MXenes. npj 2D Mater Appl 9, 114 (2025).
https://doi.org/10.1038/s41699-025-00625-6
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2025-12-24: Acknowledgement of M. Farle
Prof. Farle has been ranked by ScholarGPS.com as No 4 worldwide in the category of magnetic anisotropy. This result is based on a “revolutionary AI-driven search experience ... ScholarGPS celebrates Highly Ranked ScholarsTM for their exceptional performance in various Fields, Disciplines, and Specialties.” According to AI the scholarly contributions of Prof. Farle have placed him in the top 0.05 % of all scholars worldwide in listing of 2025 ScholarGPS. It is based on an AI analysis over his lifetime career: Highly Ranked Scholar - Lifetime.
You can also view the profile of University of Duisburg-Essen to discover other Highly Ranked Scholars as well as the rankings in various Fields, Disciplines, and Specialties.
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