Effect of Co Content on Microstructures and Magnetic Properties of Anisotropic Bulk TbCu7-type Sm-Co Nanocrystalline Magnets

摘要

The influences of Co content on the microstructures and magnetic properties of the anisotropic bulk TbCu7-type Sm-Co nanocrystalline magnets prepared by high-pressure thermal compression (HPTC) from amorphous SmCox precursors with 6.37 < x < 8.5 had been investigated. We found that with Co content x = 6.37, the TbCu7-type Sm-Co phase and a small amount of CaCu5-type Sm-Co crystallized from the precursors; from x = 6.7 to x = 8.5, only single TbCu7-type Sm-Co phase generated during the HPTC process. When x = 6.37, an obvious (00l) texture was formed, and with increasing Co content, the (00l) texture of the synthesized magnets showed a decreasing trend. With increasing Co content, the remanence B-r and saturation magnetization M-s of the nanostructure significantly increased while the coercivity H-ci gradually decreased, and at x = 7.25, a peak value of the maximum energy product (BH)(max) = 19.7 MGOe was obtained. The detailed mechanism was also discussed.