Enhanced coercivity of spark plasma sintered Zn-bonded Sm–Fe–N magnets

A high-coercivity Zn-bonded Sm–Fe–N magnet is synthesized using spark plasma sintering. Optimal post-sinter annealing results in a large coercivity of μ0Hc = 2.75 T. Transmission electron microscopy and atom probe tomography revealed the formation of a Sm–Fe–Zn–N phase on the particle surface and the presence of Fe3Zn10 at the grain boundaries, which are believed to be the cause of the enhanced coercivity.