CHARACTERIZATION OF A NEW ND-FE-O COMPOUND IN ND34FE60O6 ALLOY

The microstructure of an Nd34Fe60O6 alloy was characterized by means o f scanning electron microscopy, Anger electron multiprobe, X-ray diffr action, differential thermal analysis and thermomagnetic analysis. It was found that the equilibrium microstructure of the alloy is composed of an Nd2Fe17 matrix, an oxygen-containing Nd-rich phase and an Nd-Fe -O ternary ferromagnetic phase (referred to as T1). This phase forms v ia a peritectic reaction between the Nd2Fe17 and the Nd-rich phase at 840 degrees C. Its composition is approximately Nd36Fe54O10 and its Cu rie temperature 180 degrees C. The X-ray diffraction peaks can be inde xed on a tetragonal cell with lattice parameters a=0.771 nm and c=2.22 8 nm. This stable phase is believed to be formed from the metastable p hase (A1) in the Nd-Fe binary system as a result of the introduction o f oxygen.