High coercivity Nd-Ce-Fe-B nanostructured ribbons prepared from melt spinning technique

Abstract The Ce-substituted (Nd 1– x Ce x ) 12.2 Fe 81.6 B 6.2 ( x =0.0, 0.2, 0.4, 0.6) nanocrystalline ribbons were prepared by annealing amorphous ribbons from melt spinning. It is found that all ribbons are in a multiphase state consisting of α-Fe phase Nd(Ce)-rich phases, and RE 2 Fe 14 B (RE=Nd, Ce) phases. However, the coercivity of all annealed ribbons can reach a considerably high value without doping any heavy rare earth or other coercivity enhanced elements. A strong intergranular exchange coupling appears in these nanocrystalline ribbons. The Nd 12.2 Fe 81.6 B 6.2 ribbons with multiphase have a coercivity of about 11.3 kOe, and the coercivity decreases slightly with increasing Ce content. A coercivity of 7.5 kOe can be obtained when 60 at% of Nd is replaced by Ce ( x =0.6) due to thegrain refinement and the strong intergranular exchange coupling. This provides a practical approach of fabricating high coercivity Ce-substituted Nd-Fe-B materials.