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

• Strong textured Sm–Pr–Co/Co nanocomposite powders were prepared.
• Cobalt particles of 9–18 nm form dense coatings in the Sm–Pr–Co/Co composites.
• Effects of deposited cobalt content are studied.
• Increased cobalt content induces larger cobalt sizes and denser cobalt coatings.
• Enhanced remanences are observed in all the composite products.

Nanostructured Sm–Pr–Co/Cox (x = 0, 3, 5, 10 wt%, weight ratios between Co and Sm–Pr–Co) composite magnet powders with strong (0 0 l) 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 0.5 μm to 20 μm. 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 ∼9 nm to ∼18 nm at the expense of the Sm–Pr–Co hard-phase texture when the cobalt content is increased from x = 3 wt% to x = 10 wt%. The dense cobalt coatings grow continuous when x ⩾ 5 wt%. The mechanism for the effect of deposited cobalt on the magnetic properties of powder products is also discussed.