High-performance anisotropic Sm2Co17/Fe(Co) bulk nanocomposite magnets fabricated by two-step high-pressure thermal compression deformation

Abstract

In the realm of Sm₂Co₁₇ nanocomposite magnetic materials, it remains a challenge to fabricate anisotropic magnets by forming nanocrystalline Sm₂Co₁₇ phases with strong texture, alongside soft phases of small size and high soft phase content. In this paper, we present a novel approach for fabricating anisotropic Sm₂Co₁₇/Fe(Co) nanocomposite bulk magnets with a prominent (00l) texture of the Sm₂Co₁₇ phase, the 25 wt% content of the Fe(Co) phase, and a refined grain size of 25 nm. This fabrication is achieved using a two-step high-pressure thermal compression (HPTC) deformation process. The fabricated magnets exhibit a maximum energy product [(BH)_max] of 20.0 MGOe with a pronounced magnetic anisotropy (B_r^///B_r^⊥ = 1.23). This result is 53 % higher than the previously reported largest value [(BH)_max = 13.1 MGOe] for Sm₂Co₁₇-based nanocomposites. The magnets also exhibit a low remanence temperature coefficient (α = −0.014 %/°C) and a low coercivity temperature coefficient (β = −0.23 %/°C), demonstrating exceptional thermal stability. Our findings may improve the fabrication of anisotropic bulk Sm₂Co₁₇ nanostructure magnets for practical applications.