The effect of Nd content on the phase structure and magnetic properties of Nd–Fe alloys produced by various methods

Abstract The effects of processing methods and alloy compositions on phase structure and magnetic properties of binary Nd10+xFe90−x (x=0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4 at%) alloys, were investigated. Two types of samples produced as: long time annealed samples (LTA), and rapidly solidified ribbons (RSR), were studied. X-ray diffraction (XRD) and Mossbauer spectroscopy (MS) were applied to determine and compare the phase structures of LTA and RSR-type samples of the same compositions. For x ⩽ 1.5 alloys, XRD and MS data analysis revealed coexistence of α-Fe and Nd2Fe17 crystalline phases in LTA type samples. For x > 1.5 annealed samples, the α-Fe phase was not detected and homogeneity region attributed to Nd2Fe17 phase was observed. Different phase composition was observed for RSR samples, where mixture of: α-Fe, metastable NdFe7 (for x⩽2 at%) or Nd2Fe17 (for x>2 at%) crystalline phases with amorphous matrix was present. Furthermore, significant improvement of the magnetic properties such as the saturation polarization J s , and remanence J r was detected for the ribbon samples.