Current Status of Rare-Earth Permanent Magnet Research in USA

In the paper, we summarize the USA research activities in the past two years on high performance rare earth (R)-based (nano) composite, nanostructured and hybrid permanent magnets. The work discussed is organized in three major sections (i) isotropic magnets based on the R2Fe14B hard phase, (ii) anisotropic magnets based on the R2Fe14B hard phase and (iii) magnets with a R-Co hard phase (1:5 and/or 2:17), including ultrahigh temperature Sm-Co magnets, Sm-Co permanent magnets with almost zero reversible temperature coefficient of residual induction for critical applications and ultrahigh temperature Sm-Co magnets with small reversible temperature coefficient of residual induction.