Who: COLLOQUIUM. Prof. Gutfleisch, TU Darmstadt, Germany
Place: nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
Date: Monday, 19 June 2017, 11:00
TU Darmstadt, Material Science, Germany Fraunhofer Project Group Materials Recycling and Resource Strategy IWKS, Hanau, Germany
Magnetic materials are key components in energy related technologies, sensors and information technology. Magnets are inseparable from our everyday life. ?Green? energy technologies such as wind turbines, electro-mobility and solid state cooling, heavily rely on high performance magnetic materials which have to be available in bulk quantities, at low-cost and with tailored magnetic hysteresis properties . The realisation of these technologies is closely linked to the sustainable availability of the strategic metals for magnetism such as the group of rare earth elements (REE) namely Nd, Gd, Tb, Dy, transition metals such as Co, Ga, Ge, In, and the platinum group metals. Resource criticality is understood here as a concept to assess potentials and risks in using raw materials for certain technologies, and their functionality in emerging technologies. The concept of criticality of strategic metals is explained by looking at demand, sustainability and the reality of alternatives of rare earth elements . There is an ever-growing demand for the benchmark high performance Nd-Fe-B magnets, most importantly for use in e-motor applications, for example, in all kinds of machinery, automatization and robotics in industry (Industry 4.0). The key question will be whether Nd-Fe-B needs to be and could be substituted substantially in some of the existing and upcoming competing technologies. The arrival of a more widespread use of e-mobility and wind energy and other smart magnet usages has yet to have its impact on this application field in terms of Nd demand. No substitute is at hand for the massive amounts of high-energy density magnet materials needed to run fast moving automated industrial machinery, and the demand is expected to rise for these kinds of applications. The same applies to e-motors in hybrid electric cars, where motor designers find highly limited construction space [2, 3]. There are different concepts for wind turbines, including those that require less or no permanent magnet materials. However, permanent magnet - so-called permanent magnet direct drive wind turbines - are far superior in terms of energy efficiency and maintenance cost and seem to be becoming the dominating type of machinery in Europe and worldwide . Gas-vapour compression technology for refrigeration, heating, ventilation, and air-conditioning has remained unchallenged for more than 150 years. There is a huge demand for a smarter, more flexible and more efficient cooling technology. Magnetic refrigeration could be that alternative working without gas-based refrigerants. Energy spent for domestic cooling is expected to outreach that for heating worldwide over the course of the twenty-first century. The talk will address these different global trends and will attempt to scale bridge these challenges by discussing the modelling, synthesis, characterization, and property evaluation of novel magnetic materials considering their micromagnetic length scales and phase transition characteristics [5,6].
 O. Gutfleisch, J.P. Liu, M. Willard, E. Brück, C. Chen, S.G. Shankar, Magnetic Materials and Devices for the 21st Century: Stronger, Lighter, and More Energy Efficient (review), Advanced Materials 23 (2011) 821?842.
 R. Gauss, G. Homm, O. Gutfleisch, The resource basis of magnetic refrigeration, J. of Industrial Ecology, DOI: 10.1111/jiec.12488. (2016)
 O. Gutfleisch, M.D. Kuz´min, J. Gassmann, R. Gauss, Re-thinking rare earths: Demand, sustainability and the reality of alternatives, Proceedings of 23rd Int. Workshop on Rare Earth Magnets and their Applications, Annapolis, USA, August 2014.
 R. Gauss and O. Gutfleisch, Magnetische Materialien - Schlüsselkomponenten für neue Energietechnologien, in Rohstoffwirtschaft und gesellschaftliche Entwicklung, ed. P. Kausch und J. Matschullat, März 2016, Springer Spektrum Heidelberg, Springer-Verlag GmbH, ISBN 978-3-662-48854-6, pp. 99-118.
 K. Loewe, D. Benke, C. Kübel, T. Lienig, K.P. Skokov, O. Gutfleisch, Grain boundary diffusion of different rare earth elements in Nd-Fe-B sintered magnets by experiment and FEM simulation, Acta Materialia 124 (2017) 421-429.
 O. Gutfleisch, T. Gottschall, M. Fries, D. Benke, I. Radulov, K. P. Skokov, H. Wende, M. Gruner, M. Acet, P. Entel and M. Farle, Mastering hysteresis in magnetocaloric materials, Phil. Trans. R. Soc. A 374: 20150308. http://dx.doi.org/10.1098/rsta.2015.0308. (2016)?
Host: J. M. Pitarke