Preparation and Magnetic Properties of Nanocrystal Bulk SmCo₇ Magnets

Abstract:

Two kinds of 2:17R Sm-Co alloys, Sm₂(Fe,Cu,Zr,Co)₁₇ and pure binary Sm₂Co₁₇ were prepared, and the amorphous powder was prepared by high-energy ball milling Sm-Co alloys. The bulk nanocrystalline SmCo₇ was prepared by hot-pressing the amorphous powder, and the magnetic properties and phase composition were studied. Initial Sm₂(Fe,Cu,Zr,Co)₁₇ showed a large value of coercivity while the pure Sm₂Co₁₇ almost showed no coercivity. However, after ball milling the grain size of alloys decreased dramatically until completely amorphous. Two kinds of alloys showed the different phase composition and magnetic properties after hot-pressing. It was found that the pure Sm₂Co₁₇ bulk magnet showed a high coercivity H_c and had the 1:7H phase. On the other hand, the Sm₂(Fe,Cu,Zr,Co)₁₇ showed high saturation magnetization M_s and very low H_c since the Fe-Co and Sm₂Co₃ phase were precipitated from the alloy.

• Periodical: Materials Science Forum (Volume 815)
• Pages: 276-280
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.815.276
• Online since: March 2015
• Authors: Qian Shen*, Yi Long Ma, Jun Dong, Deng Ming Chen
• Keywords: Bulk Sm-Co, Hot-Pressing, Magnetic Properties, Nanocrystalline

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