Abstract: The microstructure of Nd_(34)Fe_(60)O_(6) alloy was characterized by means of scanning electron microscope. Auger electron multiprobe, X-ray diffraction, differential thermal analyses and thermomagnetic analyses. It is found that the equilibrium microstructure of the alloy is composed of a Nd_(2)Fe_(17) matrix, an oxygen-containing Nd-rich phase and a Nd-Fe-O ternary ferromagnetic phase (referred to T_(1)). This phase forms via a peritectic reaction between Nd_(2)Fe_(17) and Nd-rich phase at 840 ℃ . Its composition is around Nd_(36)Fe_(54)O_(10) and Curie temperature 180℃ . The X-ray diffraction peaks can be indexed on a tetragonal cell with lattice parameter of a = 0.771nm and c = 2.228nm. This stable phase is believed to be transformed from the metastable phase (A_(1)) in Nd-Fe binary system as a result of oxygen introduced.

Key words: Nd-Fe-O alloy, microstructure, phase