Archive – Functional Materials – TU Darmstadt

Archive

Picture: https://doi.org/10.1103/PhysRevMaterials.4.111401

Picture: https://doi.org/10.1103/PhysRevMaterials.4.111401

Influence of the martensitic transformation kinetics on the magnetocaloric effect in Ni-Mn-In

2020/12/01

New publication

L. Pfeuffer, T. Gottschall, T. Faske, A. Taubel, F. Scheibel, A. Y. Karpenkov, S. Ener, K. P. Skokov and O. Gutfleisch Phys. Rev. Materials 4, 111401 (2020) https://doi.org/10.1103/PhysRevMaterials.4.111401
Recently published

2020/11/18

Tailoring magnetocaloric effect in all-d-metal Ni-Co-Mn-Ti Heusler alloys: a combined experimental and theoretical study

Novel Ni-Co-Mn-Ti all-d-metal Heusler alloys are exciting due to large multicaloric effects combined with enhanced mechanical properties. We show that an optimized heat treatment leads to very sharp phase transitions in bulk alloys with large isothermal entropy changes.
New Max Planck Research Group headed by Prof. Oliver Gutfleisch to study magnets as key materials for green energy

2020/10/22

New collaboration between TU Darmstadt and Max-Planck-Institut für Eisenforschung (MPIE)
Picture: Functional Materials

Picture: Functional Materials

Functional Materials for TU charity run

2020/10/21

Running individually – donating united

Funded by the Material Science Professors, also runners and walkers from Functional Materials ran to collect money for charity. The donations will go to students facing financial distress due to the coronavirus pandemic.
Mask Production

2020/10/21

Masken gegen Corona und für gute Laune

Wie kann man Infektionen am Arbeitsplatz vermeiden? Ganz einfach, die AHA+L Regeln einhalten.
Recently published

2020/10/12

Giant voltage-induced modification of magnetism in micron-scale ferromagnetic metals by hydrogen charging

Xinglong Ye, Harish K. Singh, Hongbin Zhang, Holger Geßwein, Mohammed Reda Chellali, Ralf Witte, Alan Molinari, Konstantin Skokov, Oliver Gutfleisch, Horst Hahn & Robert Kruk Nature Communications, 11 , 4849 (2020) https://doi.org/10.1038/s41467-020-18552-z
Recently published

2020/10/12

Nanocrystalline Sm-based 1:12 magnets

A.M. Schönhöbel, R. Madugundo, J.M. Barandiarán, G.C. Hadjipanayis, D. Palanisamy, T. Schwarz, B. Gault, D. Raabe, K. Skokov, O. Gutfleisch, J. Fischbacher, T. Schrefl Acta Materialia 200 , 652 (2020) https://doi.org/10.1016/j.actamat.2020.08.075
Recently published

2020/10/12

Editor´s choice: L10 rare-earth-free permanent magnets: The effects of twinning versus dislocations in Mn-Al magnets

Yuxiao Jia, Yuye Wu, Shuang Zhao, Shulan Zuo, Konstantin P. Skokov, Oliver Gutfleisch, Chengbao Jiang, and Huibin Xu Phys. Rev. Materials 4, 094402 (2020) DOI: https://doi.org/10.1103/PhysRevMaterials.4.094402
Picture: Imants Dirba

Picture: Imants Dirba

Recently Published

2020/10/08

Synthesis and magnetic properties of bulk α″-Fe16N2/SrAl2Fe10O19 composite magnets

I. Dirba, M. Mohammadi, F. Rhein, Qihua Gong, Min Yi, B.-X. Xu, M. Krispin, O. Gutfleisch Journal of Magnetism and Magnetic Materials 518 (2021) 167414 https://doi.org/10.1016/j.jmmm.2020.167414
Recently Published

2020/09/18

Production of Fe nanoparticles from γ-Fe2O3 by high-pressure hydrogen reduction

I. Dirba, C.A. Schwöbel, A. Zintler, P. Komissinskiy, L. Molina-Luna, O. Gutfleisch Nanoscale Adv. (2020). doi:10.1039/D0NA00635A. This work is a result of our fruitful, synergistic collaborations within the Materials Science department, namely, with researchers from the Advanced Thin Film Technology and Advanced Electron Microscopy groups. We have demonstrated that by increasing the hydrogen pressure up to 530 bar, it is possible to lower the temperature necessary for complete reduction of γ-Fe 2 O 3 nanoparticles to α-Fe from 390 °C down to 210 °C. This significant improvement in reduction temperature was shown to be beneficial for the final particle morphology. Coalescence and sintering of the particles accompanied by surface area loss which occurs at elevated temperatures can be suppressed when reduction is performed at 210 °C. Interestingly, coercivity even exceeds the theoretical anisotropy field for these particles. TEM investigations reveal that the Fe nanoparticles are passivated with a Fe 2 O 3 layer resulting in a core–shell structure. These findings are relevant for applications such as catalysis and exchange-coupled nanocomposites, where fine iron nanoparticles with high surface area are required. The presented method can be extended to other metal-oxide systems.