This project is a joint project of the De Magnete group and the Atom Probe Tomography group, and was initiated by MPIE’s participation in the CRC TR 270 HOMMAGE. We also benefit from additional collaborations with the “Machine-learning based data extraction from APT” project and the Defect Chemistry and Spectroscopy group.
Magnetic materials are key components of energy conversion devices and thus improving the material’s magnetic properties is critical to enhance the sustainability of power generation and conversion. We use atom probe tomography (APT) to study the relationship between the microstructure on the nanoscale and the properties of various soft and hard magnetic materials. As demonstrated by experiments and machine-learning aided analysis, the changes in magnetic properties, e.g., magnetization, coercivity, Curie temperature and domain structure, are closely related to the variation of magnets’ microstructure. Our results help guide the design of magnetic materials.
Several magnetic systems are currently under active investigation: NdFeB, Sm(Co,Fe), CeCoCu magnets as hard magnetic alloys and CoFeNiTaAl high-entropy alloys as soft magnets.
Publication References
1.
Rao, Z.; Dutta, B.; Körmann, F.; Ponge, D.; Li, L.; He, J.; Stephenson, L.; Schäfer, L.; Skokov, K.; Gutfleisch, O.et al.; Raabe, D.; Li, Z.: Unveiling the mechanism of abnormal magnetic behavior of FeNiCoMnCu high-entropy alloys through a joint experimental - theoretical study. Physical Review Materials 4, 014402 (2020)
International researcher team presents a novel microstructure design strategy for lean medium-manganese steels with optimized properties in the journal Science
Understanding hydrogen-microstructure interactions in metallic alloys and composites is a key issue in the development of low-carbon-emission energy by e.g. fuel cells, or the prevention of detrimental phenomena such as hydrogen embrittlement. We develop and test infrastructure, through in-situ nanoindentation and related techniques, to study…
Smaller is stronger” is well known in micromechanics, but the properties far from the quasi-static regime and the nominal temperatures remain unexplored. This research will bridge this gap on how materials behave under the extreme conditions of strain rate and temperature, to enhance fundamental understanding of their deformation mechanisms. The…
In this project we developed a phase-field model capable of describing multi-component and multi-sublattice ordered phases, by directly incorporating the compound energy CALPHAD formalism based on chemical potentials. We investigated the complex compositional pathway for the formation of the η-phase in Al-Zn-Mg-Cu alloys during commercial…
Hydrogen embrittlement (HE) of steel is a great challenge in engineering applications. However, the HE mechanisms are not fully understood. Conventional studies of HE are mostly based on post mortem observations of the microstructure evolution and those results can be misleading due to intermediate H diffusion. Therefore, experiments with a…