Influence of the magnetic field annealing on the magnetic properties of some substoichiometric Nd2Fe14B melt-spun ribbons

The study of the crystallization behavior correlated with thermomagnetic measurements on the Nd8Fe82CuNb3B6 and Nd8Fe77Co5CuNb3B6 initially amorphous melt-spun ribbons suggests that the proper annealing temperature required in the obtaining of a structure free from metastable phases, must exceed 700 C. Results on the effect of the magnetic-field annealing on the investigated melt-spun ribbons are presented. There was found that the magnetic field applied during annealing the amorphous precursors affects the coercivity as well as the remanence without affecting the magnetic isotropic nature of the nanocrystalline samples. A stress relief treatment performed on magnetic-field annealed samples can result in 15% increase of the remanent ratio. Investigations on intergrain magnetic interactions via δM plot analysis are presented. (orig.)