A novel strategy to synthesize anisotropic SmCo5 particles from Co/Sm(OH)3 composites with special morphology

Abstract

In this study, we report a new strategy for preparing magnetically anisotropic SmCo₅ single crystal particles by reductive annealing of precursors with specially designed nanostructures. The precursors containing urchin-shaped Co clusters and Sm(OH)₃ nanorods were synthesized by a hydrothermal process. Then we coated these precursors of Co/Sm(OH)₃ nanocomposites with Ca(OH)₂, and the following thermal reduction generated SmCo₅ particles, where the original size and morphology of the precursor were basically preserved after undergoing high temperature annealing. The single crystalline SmCo₅ particles exhibit strong magnetic anisotropy and excellent room temperature magnetic properties: remanence of 8.1 kG, coercivity of 25.7 kOe, and a maximum energy product of 15.8 MGOe, which is one of the highest maximum energy products for chemically synthesized nanostructured SmCo₅ particles presently reported.