Permanent-magnet properties of Sm-Ce-Co-Fe-Cu alloys with compositions between 1-5 and 2-17

This paper describes magnetic and metallographic properties of rare-earth-cobalt alloys of (Sm, Ce) (Co, Fe, Cu) z ( 5 \lsim z \lsim 8.5 ). Some alloy compositions exhibit anomalously large coercive forces and have excellent potential for permanent-magnet application. The composition Sm 0.75 Ce 0.25 (Co 0.81 Fe 0.04 Cu 0.15 ) 7.2 shows a maximum energy product of 20.2 MG Oe, which is the highest among the compositions studied. Most alloys exist in the CaCu 5 -type crystal structure although some show a few of very weak superlattice lines characteristic of hexagonal Th 2 Ni 17 . When aged at about 960°C, the alloys show another phase in addition to the aforementioned structures.