The 2-17 type Sm2-xHRExCo10Cu1.5Fe3.2Zr0.2(HRE=Gd, Tb, Dy, Ho, Er) magnets with low temperature coefficient

Composition and properties of Sm2-xHRExCO10Cu1.5Fe3.2Zr0.2(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=18.0MGOe, 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=22.6MGOe and α =-0.018%/° C from 20° to 100°C. A magnet with X=0.58 Gd possesses a(BH)max=16.7MGOe 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)maxof 4.5 to 4.7 MGOe. These both materials show promise for use in magnetic circuit as temperature compensating magnets.