Structure and magnetic properties of Cu-doped SmCo6.7−xCuxCr0.3 magnets

Structure and magnetic properties of mechanically alloyed Cu-doped SmCo6.7−xCuxCr0.3 (x=0.1–0.7) magnets have been systematically studied. The magnetically hard main phase is found to be of Th2Ni17 type in the SmCo6.7−xCuxCr0.3 alloys. A small amount of Cu addition is favorable for the formation of the 2:17 phase/Co nanocomposite structure in the alloys. The increase of Cu doping results in more Cu precipitating in the alloys with separating the grains, which significantly enhances the intrinsic coercivity Hci of the alloys and weakens the exchange coupling between the magnetically hard and soft phases. The magnetization reversal processes of the magnets have been discussed, upon the measurement of the recoil curves.