Effect of composition on the magnetic properties of (Ce1−<i>x</i>Nd<i>x</i>)13.5 (Fe1−<i>y</i>−<i>z</i>Co<i>y</i>Si<i>z</i>)80B6.5 sintered magnets

Abstract

The influences of varying cerium, neodymium, cobalt, and silicon concentrations on the magnetic properties of Ce-Fe-B type magnets were investigated. The results indicated that magnets containing 13.5 at.% of cerium exhibits superior magnetic properties to those exhibited by magnets with higher rare-earth element compositions. High-temperature annealing of the cast alloy containing 13.5 at.% cerium at 1010 °C for 120 min results in the elimination of the α-Fe phase. Increasing the cobalt concentration from 0 to 17 at.% raises the Curie point from 174 °C to 324 °C. The addition of 1 at.% of silicon to the alloy improves intrinsic coercivity by up to 100%. The substitution of up to 5.4 at.% of cerium by neodymium increases magnetic properties of sintered magnets with a 13.5 at.% total rare-earth content. Neodymium contents exceeding 5.4 at.% decrease coercivity. The highest maximum energy product of 27.2 MGOe was exhibited by magnets with a composition of Ce8.1Nd5.4Fe62Co17SiB6.5.