Magnetism of Nd-Fe films as a model of grain boundary phase in Nd-Fe-B permanent magnets

摘要

To clarify the magnetism of an amorphous grain boundary (GB) phase in Nd-Fe-B sintered magnets, the magnetic properties of Nd_(100-x)Fe_x films with various compositions have been investigated both experimentally and theoretically. The model films exhibit ferromagnetism at room temperature when the Nd content is lower than 70 at. %. First-principles calculations indicate ferromagnetism in fcc Nd-Fe alloys for x ＜ 70, which supports recent experimental works on the intergrain exchange coupling of Nd-Fe-B sintered magnets.