The 2-17 type Sm<inf>2-x</inf>HRE<inf>x</inf>Co<inf>10</inf>Cu<inf>1.5</inf>Fe<inf>3.2</inf>Zr<inf>0.2</inf>(HRE=Gd, Tb, Dy, Ho, Er) magnets with low temperature coefficient

Composition and properties of Sm 2-x HRE x CO 10 Cu 1.5 Fe 3.2 Zr 0.2 (HRE=Gd,Tb,Dy,Ho,Er) magnets have been investigated. All alloy powders used in this study were made by the Reduction-Diffusion (R/D) process. The results indicate that Er or Gd-containing magnets have higher magnetic properties than Tb,Dy or Ho-containing magnets. Composition near X=0.8 yields the lowest temperature coefficient. The best properties obtained for a magnet with X=0.8 Er are: (BH)\max=18.0 MGOe, with a reversible temperature coefficient (α) of nearly zero from 20° to 80°C. A magnet with X=0.4 Er attained values of (BH)\max=22.6 MGOe and α =-0.018%/° C from 20° to 100°C. A magnet with X=0.58 Gd possesses a (BH)\max=16.7 MGOe and α =-0.013 %/°C from 20° to 100°C. The magnets with X=2 Er or X=2 Gd have positive α and (BH)\max of 4.5 to 4.7 MGOe. These both materials show promise for use in magnetic circuit as temperature compensating magnets.