The Effect of Antiferromagnetic Element Manganese on The Mmagnetic Pproperties of α -Fe/Nd_2Fe_(14)B Mmagnets

摘要

The addition of manganese into Nd_9Fe_(85-x)Mn_xB_6 (X=0,0.5,1 ) was found to enhance the magnetic properties of α -Fe/Nd_2Fe_(14)B magnets. After optimal annealed, the coercivity and remanence ratio increased from 0.34MA/m to 0.4MA/m and from 0.70 to 0.72, respectively, for the increase of x from 0 to 1 . The XRD patterns indicated the addition of manganese could promote crystallization of as-spun samples. Moreover, the XRD spectra showed almost same grain sizes obtained for the optimal annealed samples. Thermomagnetic analysis (TMA) measurement indicated that the doping of Mn reduces the T_c of the Nd_2Fe_(14)B phase and raises that of α -Fe phase in the system. It is believed the exchange coupling between the Nd_2Fe_(14)B phase and α -Fe phase was partly changed by Mn addition, which is the reason for the enhanced magnetic properties and the change of T_c.