Atom probe characterization of an /spl alpha/-Fe/Nd/sub 2/Fe/sub 14/B nanocomposite magnet with the remaining amorphous phase

We have investigated the microstructural feature of a nanocomposite permanent magnet composed of a-Fe, Nd2Fe14B, and an amorphous phase by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM). A unique feature of this nanocomposite magnet is the presence of the grain boundary amorphous phase when the optimum magnetic properties are obtained [I]. This type of microstructure may cause weaker exchange interaction between soft and bard grains, which may realize the optimum microstructure for superior hard magnetic properties proposed by Fukunaga et al. [21.