Anisotropic bulk SmCo7 nanocrystalline magnets with high energy product

Abstract

Realizing grain alignment along easy magnetization axis in bulk SmCo7 nanocrystalline materials is crucial for their development as high-performance high-temperature magnets, yet it remains challenging. Here, we report the fabrication of anisotropic bulk SmCo7 nanocrystalline magnets with a small grain size of ∼20 nm and a (00l) texture using high-pressure thermal compression starting from partially amorphous precursors. The synthesized magnet exhibits a high energy product of 18.4 MGOe, 40% larger than the reported highest value (13 MGOe) for bulk nanostructured SmCo7 magnets, and outperforms its anisotropic coarse-grained counterpart. Moreover, our magnet shows a low coercivity temperature coefficient of β = -0.19%/°C. These findings make an important step toward the fabrication of oriented bulk nanostructures for practical applications.