Mitigation strategies along the resource critical value chain of rare earth magnets

Speaker: Prof. Oliver Gutfleisch

Host: Prof. Dierk Raabe

Magnets are key enablers for the green energy transition. High performance hard and soft magnets are crucial components of energy-related technologies, such as direct drive wind turbines and e-mobility. They are also important in robotic, medicine, sensors, actuators, information technology, defence and space applications.

The rare earth elements (REEs) are the epitome of critical raw materials (CRMs), more recently we observe a geopolitical weaponizing of the REEs. They are essential constituents of the highest performing magnets and are highlighted in the (EU) Industrial Ecosystems and a net zero emission scenario.

Important questions arise around the different mitigation scenarios addressing the criticality of the strategic REEs; there are many bottlenecks along the supply and value chain. Supply deficits will endanger the development of technologies which abate the climate change and will also impact on other strategic sectors. This supply chain has to be secure, affordable and sustainable; and in order to achieve this, we need the diversification of primary CRMs, material science and process solutions. The total tonnage of REEs used in Germany is actually relatively small, but their economic leverage is enormous.

I will explain material science-based concepts for highest performing magnets along alloy and microstructure design, substitution and recycling and developing a REE circular economy to bridge the supply gap and increase European resilience.

Finally, I will address cooling which is more than space cooling, process cooling, and the cold chain. Sustainable cooling is about resilience and equity and we need to cut its energy and carbon footprint. I introduce our university spin-off company Magnotherm GmbH; their worldwide unique beverage cooler and supermarket display cooler are based on the magnetocaloric effect (MCE), energy efficient, refrigerant free, sustainable and safe. Magnetic refrigeration technology is however again a material intensive but potentially disruptive technology, with an interesting outlook into hydrogen liquefaction and other special environments.

[1] O. Gutfleisch, M. A. Willard, E. Brück, C. H. Chen, S. G. Sankar, and J. P. Liu, Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient. Adv. Mater. 23 (2011) 82.

[2] K.P. Skokov and O. Gutfleisch, Heavy rare earth free, free rare earth and rare earth free magnets - vision and reality, Scripta Materialia View Point Set, 154 (2018) 289-294.

[3] T. Gottschall, K.P. Skokov, …., O. Gutfleisch, Making a cool choice: the materials library of magnetic refrigeration, Progress Report in Advanced Energy Materials 9 no. 34 (2019) 1901322.

[4] M. Schönfeldt, …, J. Gassmann, O. Gutfleisch, Functional Recycling and Reuse of Nd-Fe-B Permanent Magnets from Various Waste Streams for a more Sustainable and Resilient Electromobility, Adv. Eng. Mat. (2025) 2402815.

[5] L. Han, …., O. Gutfleisch, D. Ponge, D. Raabe, Z. Li, Ultrastrong and ductile soft magnetic high-entropy alloys via coherent ordered nanoprecipitates, Advanced Materials 2102139 (2021).

[6] S. Giron, …, O. Gutfleisch, L. Molina-Luna, B. Gault, K.P. Skokov, Identifying grain boundary and intragranular pinning centres in Sm2(Co,Fe,Cu,Zr)17 permanent magnets to guide performance optimisation, Nature Communications 16 (2025) 11335.

{6] A. Durgun, I. Dirba, O. Gutfleisch, Combining Grain Boundary Diffusion and Segmentation: a novel production route for Resource-Efficient Nd–Fe–B Magnets, Scripta Materialia 275 (2026) 117164.

[7] https://www.magnotherm.com/

[8] J. Liang, J. Pickett, …, K. Skokov, O. Gutfleisch, T. Gottschall, M. Fries, D. Benke, Polaris: from laboratory prototypes to market-ready sustainable magnetic beverage coolers, Applied Thermal Engineering 284 (2026) 129144.

Registration: https://plan.events.mpg.de/event/805/registrations/824/

The colloquia series is organized by the International Max Planck Research School on Sustainable Metallurgy (IMPRS SusMet)