Magnetic reversal in single-phase nanocrystalline Sm-Fe-N alloys and a two-phase remanence enhanced (Sm2Fe17N3+ alpha -Fe) alloy

The nucleation fields of isotropic nanocrystalline single-phase Sm-Fe-N magnets prepared by mechanical alloying have been determined experimentally. Single-phase Sm-Fe-N magnets possess a distinct angular dependence of the nucleation field, giving rise to a nucleation-controlled magnetic reversal process. The influence of the substitution of Co and Ti for Fe is discussed. Additionally, two-phase (Sm2Fe17Nx+ alpha -Fe) alloys have been investigated by measuring the perpendicular and the parallel components of the magnetization and their remanence. Remanence enhancement has been observed; that is, the magnetic reversal in these two-phase alloys is strongly affected by intergrain exchange interaction. This may give rise to cascades of magnetization reversal due to collective processes. A phenomenological explanation of the magnetic reversal in these systems is suggested.