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2023-08-12: Pinned magnetic moments in the collinear antiferromagnet PdMn
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Pinned magnetic moments in the collinear antiferromagnet PdMn
In a joint research work within the CRC/TRR270 "Hysteresis design of magnetic materials for efficient energy conversion" Nicolas Josten (PhD candidate) in project A04 could show that annealing the collinear antiferromagnet PdMn with excess Pd in a magnetic field produces strongly pinned magnetic moments in the annealing field direction. This behavior can be understood with the help of the magnetic-field-biased diffusion model. Here, the magnetic field creates an energy difference between the two possible occupations of the antiferromagnetic Mn-sublattices by the Pd-excess atoms. This, mediated by diffusion, leads to an imbalance in the amount of the Pd-excess atoms in these sublattices and, subsequently, to an imbalance in the total magnetization of the sublattices. For Details see: Annealing time, temperature, and field dependence of pinned magnetic moments in the collinear antiferromagnet PdMn
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2023-08-09: Helical magnetic structure of epitaxial films of nano-laminated Mn2GaC MAX phase
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In a multinational collaboration we could identify a complex magnetic arrangement of Mn magnetic moments, that is a helical magnetic structure consisting of the ferromagnetically coupled Mn-C-Mn slabs that are twisted across the Ga layer by 167.2 deg with respect to the next Mn-C-Mn slab. As a result, the magnetic structure presents a spiral propagating along the out-of-plane direction (hexagonal c axis) with a pitch of around 14 lattice constants. For Details see: Annealing time, temperature, and field dependence of pinned magnetic moments in the collinear antiferromagnet PdMn
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2023-07-18: Femtosecond Laser Ablation-Induced Magnetic Phase Transformations in FeRh
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In a trilateral French-Spanish-German collaboration we investigated the ablation properties of FeRh films. We found that the initial FeRh film displayed a reversible antiferromagnet-ferromagnet phase transition and the laser-ablated structures exhibited irreversible changes in their magnetic properties. Fluence-resolved measurements clearly demonstrate that the ablation threshold coincides with the threshold of the antiferromagnet-to-ferromagnet phase transition. For details see: Femtosecond Laser Ablation-Induced Magnetic Phase Transformations in FeRh Thin Films .
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2023-07-18: Easy up-scalable synthesis for ferrite nanoparticles
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2023-06-29: Ni-Mn-Sn Heusler alloys manufactured by e-beam and laser powder bed fusion
 | In a recent joint publication of the CRC/TRR270 we published a comparative study of additive manufacture Ni-Mn-Sn Heusler alloys.
Using an uncommon PBF-EB/M spot melting strategy, for the first time, crack-free Ni-Mn-Sn bulk material were produced and the chemical, microstructural, and magnetic properties were analyzed. Results on the magnetocaloric effect of the consolidated samples are reported. For details see S.-K. Rittinghaus et al. , Additive Manufacturing Letters 7 (2023) 100159 . |
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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.
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