Phase composition, structure and magnetic behaviour of low neodymium rapid-quenched Nd-Fe-B alloys

Abstract

Phase composition, structure and magnetic behaviour of two low neodymium rapid-quenched (R/Q) Nd-Fe-B alloys differing in way of preparation, centrifugal atomization and melt spinning, were studied and compared using Mössbauer spectroscopy (MS), X-ray diffraction (XRD), thermomagnetic analysis (TM) and SQUID magnetic measurements. Better hard magnetic characteristics of the melt-spun material are explained on the basis of the differences in content of surface and/or interface Fe(Nd,B) phases. Their significant presence in the centrifugally atomized material lowers the content of Fe3B, Fe2B, α-Fe, and Nd2Fe14B phases that are responsible for the magnetic qualities of the material. There are just subtle differences in the phase composition of both materials after thermomagnetic measurement, where the α-Fe phase prevails as a product of thermal decomposition.