The future of rare earth-transition metal magnets of type RE2TM17 (invited)

Abstract

A brief review of the development of RE₂TM₁₇ permanent magnets is followed by a summary of the state‐of‐the‐art. Excellent magnetic properties have been achieved in the laboratory for single‐phase 2:17 and two‐phase, precipitation hardened magnets of ∼2:15 stoichiometry. Both achieve reduction of cobalt content to ∼50 wt.% by transition metal substitution and the precipitation hardened type exhibit improved temperature characteristics. Recent improvements in coercivity make high volume application practical if the more abundant light rare earths can be successfully substituted for samarium.