Fabrication and magnetic properties of anisotropic SmCo3/Fe(Co) bulk nanocomposite magnets

Abstract

For bulk SmCo3 system hard-soft magnetic nanocomposites, it remains a challenge to fabricate an anisotropic magnet by forming a strong texture for the nanocrystalline SmCo3 phase. In this paper, we report the fabrication of a bulk anisotropic SmCo3/Fe(Co) nanocomposite magnet with a strong (00 l) texture for the SmCo3 phase and a small grain size of 21 nm for the Fe(Co) phase. Good results were achieved by controlling the nucleation and growth of the nanocrystals from the amorphous matrix using large stress and strain. The synthesized magnet exhibited a high-energy product of 17.0 MGOe, which was 26% larger than the reported highest value of 13.5 MGOe for SmCo3-based nanocomposites and 314% higher than 4.1 MGOe for the corresponding pure SmCo3 magnets. Moreover, these magnets possessed small remanence and coercivity temperature coefficients of α = −0.018%/°C and β = −0.24%/°C, which were much lower than those α = −0.14%/°C and β = −0.31%/°C for pure SmCo3 magnets and α = −0.073%/°C and β = −0.30%/°C for SmCo3/Fe(Co) isotropic nanocomposite. These findings are an important step toward the practical application of the SmCo3-based nanocomposite.