Posted on behalf of Ros Daw, Senior Editor, Nature
Hard disk drives, DVDs and CDs — along with many clean energy devices such as wind turbines and electric vehicles — all demand high-quality permanent magnets such as neodymium-iron-boron and samarium-cobalt for their operation. Increasing demand in these products has meant the cost of the rare-earth metals forming these magnets has gone up; and the Western world is already paying a premium to China for the raw materials.
At the ‘Magnets’ session of the ‘Energy Critical Materials’ symposium, researchers presented a variety of routes to reduce the dependence of rare-earth metals in high-quality magnetic materials. George Hadjinpanyas described rare-earth-lean nanocomposites comprised of exchange-coupled soft and hard magnetic phases from powder precursors (1). Ryan Ott reported a promising method of recycling rare-earth metal alloys using a magnesium extraction method (2). And in a third talk, Arif Mubarok provided insights to optimise rare-earth-free (soft) magnet FeNi with inspiration from novel crystal structures found in meteorites (3).
The session highlighted that the burgeoning clean-energy-device industry is actually introducing a whole new set of sustainability issues with regard to the raw materials forming their components. There is clearly a need for a more holistic approach in order to develop truly sustainable technologies.
(1) The Drive for Permanent Magnets with Significantly Lower or No Rare Earth Content; George Hadjipanyas; Symposium D; 2012 Fall MRS.
(2) Permanent Magnet Alloys Synthesized from Recycled Rare Earth Metals; Ryan T Ott, Lawrence L Jones, Kevin W Dennis, R. William McCallum; Symposium D; 2012 Fall MRS.
(3) Microstructural and Magnetic Characterization of Tetrataenite, FeNi — A Potential Candidate for a Rare-earth-free Permanent Magnet; Arif Mubarok; Nina Bordeaux, Joseph L Goldstein, Laura H Lewis; Symposium D; 2012 Fall MRS.