Microstructure and magnetic properties in Mn-doped Nd–Fe–B magnets

The effect of the addition of antiferromagnetic element Mn on the local structure and the magnetic properties of Nd9Fe85B6 magnets has been studied. It was found that the microstructure and local structure heavily depended on both the Mn addition and the quenched speed. The Mn additions could promote the order degree around Fe atom in as-spun samples. After appropriate annealing, the completely crystallized samples were obtained. It showed that the difference of the local structures around Fe atoms almost disappeared and the hard magnetic properties, especially the coercivity was enhanced. It is presumed that the enhanced hard magnetic properties were attributed to the enhancement of the exchange coupling, which is between the hard phases and the soft phases.