Facile synthesis of anisotropic nanostructured Sm–Pr–Co/Co magnet composites with dense coatings of fine cobalt nanoparticles

Abstract

Nanostructured Sm–Pr–Co/Cox (x=0, 3, 5, 10wt%, weight ratios between Co and Sm–Pr–Co) composite magnet powders with strong (00l) hard-phase textures and dense coatings of fine cobalt nanoparticles are prepared via electroless cobalt deposition on textured nanocrystalline Sm–Pr–Co hard magnet materials. The Sm–Pr–Co particles are irregularly shaped with sizes from 0.5μm to 20μm. The effects of the deposited cobalt content on the hard-phase texture, morphology, and magnetic properties of the Sm–Pr–Co/Co composite powders are investigated. The cobalt particles increase from ∼9nm to ∼18nm at the expense of the Sm–Pr–Co hard-phase texture when the cobalt content is increased from x=3wt% to x=10wt%. The dense cobalt coatings grow continuous when x⩾5wt%. The mechanism for the effect of deposited cobalt on the magnetic properties of powder products is also discussed.