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

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 ≤ × ≤ 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 CaCu
₅
-type Sm-Co crystallized from the precursors; from x = 6.7 to x = 8.5, only single TbCu
₇
-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.