Mechanically alloyed Sm-Fe-N magnets with addition of Ga

The magnetic properties and microstructure of Sm-Fe-N magnets with addition of Ga were studied. It was found that the coercivity initially increased and than decreased when Ga content exceeded 0.5 at%. Ga substituted Fe in the lattice of Sm/sub 2/Fe/sub 17/ phase and formed a (Sm,Ga)-rich phase at grain boundaries. Deterioration of the magnetic properties, for Ga contents above 0.5 at%, we attribute to a reduced nitrogen solubility in the lattice of the Sm/sub 2/(Fe,Ga)/sub 17/N/sub x/ phase and towering of its anisotropy constants.