Authors: Laura H Lewis Félix JiménezVillacorta
Publish Date: 2012/07/18
Volume: 44, Issue: 1, Pages: 2-20
Abstract
Permanent magnet development has historically been driven by the need to supply larger magnetic energy in ever smaller volumes for incorporation in an enormous variety of applications that include consumer products transportation components military hardware and clean energy technologies such as wind turbine generators and hybrid vehicle regenerative motors Since the 1960s the socalled rareearth “supermagnets” composed of iron cobalt and rareearth elements such as Nd Pr and Sm have accounted for the majority of global sales of highenergy–product permanent magnets for advanced applications In rareearth magnets the transitionmetal components provide high magnetization and the rareearth components contribute a very large magnetocrystalline anisotropy that donates high resistance to demagnetization However at the end of 2009 geopolitical influences created a worldwide strategic shortage of rareearth elements that may be addressed among other actions through the development of rareearthfree magnetic materials harnessing sources of magnetic anisotropy other than that provided by the rareearth components Materials engineering at the micron scale nanoscale and Angstrom scales accompanied by improvements in the understanding and characterization of nanoscale magnetic phenomena is anticipated to result in new types of permanent magnetic materials with superior performanceThis work has been supported in part by ONR Grant N000141010553 by the US Department of Energy’s Advanced Research Project Agency Energy ARPAE Award DEAR0000186 by the US Department of Energy Office of Basic Energy Sciences Division of Materials Sciences and Engineering under Grant DESC000525 and by Northeastern University Special thanks are due to S Constantinides Arnold Magnetic Technologies Corporation Prof K Barmak Columbia University and Prof J Shield University of Nebraska–Lincoln for assistance and consultation
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