Preparation and Magnetic Properties of Anisotropic (Sm,Pr)Co₅/Fe Nanocomposites Particles via Electroless Plating

Abstract

Anisotropic (Sm,Pr)Co5/Fe nanocomposites particles were prepared by electroless plating iron on the surface of (Sm,Pr)Co5nanoflakes after being prepared by ball milling for 4 h. A uniform and continuous coating layer was obtained due to the addition of complexing agent and the particle size of the reduced Fe particles was in the range of 10~20 nm. When the nominal addition of Fe was 15 wt%, the nanocomposites show enhanced remnant and saturation magnetization:Mr=53.35 emu/g,Ms=73.08 emu/g compared to the noncoated nanoflakes withMr=48.52 emu/g,Ms=60.15 emu/g, while the coercivity drops from 10.33 kOe to 8.89 kOe. The effect of Fe content on the magnetic properties of the magnets is also discussed.

Phase- and Composition-Tunable Hard/Soft Magnetic Nanofibers for High-Performance Permanent Magnet

“…Many efforts have been made to synthesize exchange-spring nanomagnets using different ex situ approaches including conventional physical techniques such as mechanical mixing with individual magnetic powder, − self-assembly, − and electroless deposition of a soft magnet on a hard magnet. − Such magnetic composites commonly possess a predominance of a long-range dipolar interaction of the hard–hard and soft–soft magnetic phases based on the uneven coupling between the hard and soft magnetic phases, resulting in enervating the exchange-coupling interaction and further deteriorating magnetic performance . Moreover, even the use of mechanical power for powder mixing or a strong acidic solution for electroless coatings causes fast oxidation of the metallic magnets and, at worst, phase decomposition into a nonmagnetic phase because metal magnets are vulnerable to harsh process conditions …”

Exchange-Coupling Interaction in Zero- and One-Dimensional Sm2Co17/FeCo Core–Shell Nanomagnets

“…Since then, many different RE-based spring magnets with soft magnetic sheaths have been investigated. For example, SmCo 5 /FeNi, (Sm,Pr)­Co 5 /Fe, and NdFeB/Fe were synthesized through an electroless plating process that easily forms a continuous nanoscale coating layer on a raw RE magnet. − …”

“…The remainder behaves as an independent soft phase, resulting in magnetic decoupling, which is no longer fit for an ideal exchange-coupled magnet. Nevertheless, the majority of electroless plating studies is limited to Nd 2 Fe 14 B and SmCo 5 powders. − ,,, …”

“…Nevertheless, the majority of electroless plating studies is limited to Nd 2 Fe 14 B and SmCo 5 powders. [8][9][10]12,13,15 Herein, with a view to overcoming the structural and material limitations, we chose magnetically hard Sm 2 Co 17 and soft Fe 11 Co 5 , which has the highest saturation magnetization (i.e., 240 emu/g) among soft magnetic materials, to synthesize 1-D and 0-D hard−soft core−shell nanomaterials and assess their potential as exchange-spring structures for achieving maximum magnetic properties (Figure 1). We verified the optimal microstructure for the exchange-coupled nanomagnet by comparing the morphological and magnetic characteristics of each structure.…”