The magnetic properties of melt-spun Nd9Fe85−xMnxB6(x=0–1) ribbons

Abstract The magnetic properties of Nd 9 Fe 85− x Mn x B 6 ( X =0,0.5,1) exchange coupling magnets were investigated by differential thermal analysis, X-ray diffraction, vibrating sample magnetometer and Mossbauer spectroscopy. It was found that manganese addition in melt-spun Nd 9 Fe 85 B 6 can promote crystallization and enhance both coercivity and remanence ratio. The optimum coercivity and remanence ratio increases from 4.3kOe and 0.70 to 5.0 kOe and 0.72, respectively. Thermomagnetic analysis showed Mn doping reduces the Curie temperature of the Nd 2 Fe 14 B phase and raises that of α-Fe phase. The volume fractions of α-Fe and Nd 2 Fe 14 B phase measured by Mossbauer spectroscopy appeared slightly different from Mn addition content. It is presumed that the enhancements in hard magnetic properties may be attributed to the change of the environment for the phases due to Mn addition.