Structure and magnetic properties of Cu-doped Sm Co6.7-x Cux Cr0.3 magnets

Abstract

Structure and magnetic properties of mechanically alloyed Cu-doped Sm Co6.7-x Cux Cr0.3 (x=0.1-0.7) magnets have been systematically studied. The magnetically hard main phase is found to be of Th2 Ni17 type in the Sm Co6.7-x Cux Cr0.3 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. © 2007 American Institute of Physics.