Effects of Fe, Cu, Zr, and Ti on the magnetic properties of SmCo-1:7 magnets

Abstract

The effect of Fe, Cu, Zr, and Ti substitution on

magnetic properties of SmCo 1 : 7 magnets at temperatures up to

500 C were studied. As-milled amorphous Sm(Co,Fe,Cu,Ti???Zr)7

magnets crystallized in the TbCu7-type structure after annealing

at 750 C for 2 h. A room-temperature intrinsic coercivity of

around 2.5 T is obtained for compositions SmCo6 4Zr0 2Ti0 4 and

SmCo6 4Fe0 1Zr0 1Ti0 4. The high coercivity of the ball-milled

SmCo7 Ti magnets is attributed to the strong pinning of

the walls of the ???interaction domains?? by the network of grain

boundaries between the nanocrystalline grains. The virgin curve

of the ball-milled samples is suggestive of strong domain wall

pinning.