Structural and Magnetic Properties of Nd(Fe,Mo)₁₂N_x Compounds Produced by Strip-Casting Method

The strip casting (SC) technique is employed to fabricate Nd(Fe,Mo)₁₂N_x magnets. The crystallographic structure, intrinsic and permanent magnetic properties, as well as the microstructures of the compound are investigated. There are prominent advantages for the SC Nd-Fe-Mo alloys and their nitrides when compared with the samples prepared by the conventional casting (CC) method: (1) SC technique rebounds to the formation of the compounds crystallizing in a ThMn₁₂-type structure. A single-phased host alloy Nd(Fe,Mo)₁₂ can be directly prepared by strip casting without any isothermal annealing. Accordingly, lower energy cost and less rare earth demand notablely benefit the manufacture processing from a point of economizing. (2) The intrinsic magnetic properties, such as Curie temperature T_c, saturation magnetization M_s and anisotropy field H_a of the SC sample exceed the CC sample due to a phase forming condition with less-Mo-depended. (3) The microstructure studies also demonstrate that the SC compound contains finer grains, better-proportioned phase distribution than the CC compound. Optimized final particles are observed aligned in their easy axis and the energy product of powder sample is up to (BH)_max~22 MGOe (176 kJ/m³).