Structure and magnetic properties of anisotropic bulk TbCu_7-type (Sm, Pr)Co_7 nanocrystalline magnets

摘要

Fabricating anisotropic bulk TbCu_7-type RCo_7 nanocrystalline magnets is of great significance for their development as high-performance high temperature magnets. In this paper, anisotropic bulk TbCu_7-type (Sm_(0.6)Pr_(0.4))Co_7 nanocrystalline magnets have been prepared using high-pressure thermal compression (HPTC). The (Sm_(0.6)Pr_(0.4))Co_7 magnet had a strong (002) crystallographic texture and a small grain size of -20 nm, yielding a maximum energy product of (BH)_(max) = 19.5 MGOe. The magnets showed a coercivity temperature coefficient of β = -0.21%/°C from room temperature (RT) to 300 °C, better than that -0.23%/°C of the SmCo_7 magnets prepared in the same conditions.