Permanent magnets are a key technology for modern society with applications in air conditioning, mobility or power generation. The measured coercive fields in modern permanent magnets reach only a small fraction of the theoretical values. A series of experimental studies have shown that discontinuities and misalignment at the atomic scale significantly affect the macroscopic coercivity. In this project, we develop a quantitative theory of coercivity, taking into account the local atomic structure, the spatial variation of the intrinsic magnetic properties, and the physical microstructure of the magnet. To achieve this goal we bridge the length scale between ab-initio simulations, atomistic spin dynamics and continuum micromagnetic simulations. Atomic defects at interfaces and grain boundaries will be considered already at the smallest possible length scale, the unit cells of the material composition. The developed theory is guided by well described magnetic materials to validate the system throughout the progress of the project.
The 13th International Symposium on Hysteresis Modeling and Micromagnetics (HMM 2023) was held in Vienna from June 4-7,02023 (www.asc.tuwien.ac.at/hmm2023). For the project, Alexander Kovacs presented a poster entitled “Finite Hex Element Adaptive Mesh Refinement of Demagnetizing Field Computation”.
Our project partners from Ostrava were also represented with a poster entitled "The role of the interface and ferromagnetic alloying on the interlayer exchange coupling". We used the symposium for a joint project meeting. Participants from our department were Alexander Kovacs, Thomas Schrefl and Markus Gusenbauer. Our colleagues from Ostrava were represented by Dominik Legut and Sergiu Arapan. We gave each other an update on ongoing developments and discussed upcoming steps. We also planned a visit from two experts, Erol Girt from Simon Fraser University in Canada and Hossein Sepehri-Amin from the National Institute for Materials Science in Japan, who provide important experimental input for our joint project.
On May 11, 2023 the talk "Multiscaling strategies in computational magnet design" was presented at the "Going Green CARE INNOVATION 2023" in Vienna (www.careinnovation.eu) . Thereby parts of the project could be presented to a larger audience. The program included the latest developments in circular economy, clean production, resource efficiency, climate change and much more, presented by leading experts from industry, academia and the public sector from around the world. The talk was presented as part of a joint workshop titled "Interdisciplinary team up to escape the rare earth trap." The team consists of the Erich Schmid Institute of Materials Science of the Austrian Academy of Sciences in Leoben, the Johannes Kepler University Linz and the University for Continuing Education Krems. The idea of the workshop was the connection of material scientists, engineers and social scientists to gain benefit from interdisciplinary collaborations for finding the most sustainable solutions for magnetic material design.
On May 20,2022 we were able to inspire young and old at the Long Night of Research 2022. The influence of permanent magnets on electromobility was demonstrated at a hands-on station. Those interested were able to find out how magnets influence the performance of electric motors with simple experiments. With our project we were able to show how important it is to develop permanent magnets without critical rare earths materials.
Markus Gusenbauer gave a talk at JEMS2022 on July 26, 2022 entitled: "Coercivity analysis of twin boundaries". The talk was virtually shown at the hybrid event in Warsaw, Poland (https://jems2022.pl).
On July 13, 2022, we organized a workshop at the Junge Uni on the Krems campus. Children between the ages of 10 and 13 learned about how an electric motor works. They were able to make a small electric motor and experience how the strength of a magnet affects the power of a motor. Thomas Schrefl, Harald Özelt and Markus Gusenbauer were the supervising researchers at the workshop.
The first kick-off meeting took place on July 4, 2022 in Krems. Participants were Dominik Legut and Sergiu Arapan from TU Ostrava, Czech Republic. And from Krems, Thomas Schrefl, Markus Gusenbauer, Harald Özelt, Alexander Kovacs and Qais Ali were represented. There was also a guest researcher from Ukraine, Dr. Oleksandr Hrushko. Among the topics discussed were the first phase of the project, in which we are focusing on the Fe/Ni material combination and implementing the adaptive grid for the microstructures of the simulations. We also discussed the possibility of linking the characterization of the mechanical properties of magnets to the project. Afterwards, a social evening took place at a local “Heuriger” with a view to the Danube.
FWF Projekt: I I 5712-N
Experiments and simulations for physics-informed machine learning to design nedoymium-iron-boron permanent magnets
Joint European Magnetic Symposia (JEMS 2023), 31/08/2023
Recent activities on the applications of machine learning in micromagnetics
IEEE Advances in Magnetics (AIM2023), 17/01/2023