Preparation and properties of Nd-Fe-B/Fe nanocomposite magnets

Nd-Fe-B/alpha-Fe nanocomposite magnets with high magnetic properties were successfully fabricated through a sonochemical process with carbonyl iron as Fe precursor and subsequently SPS. Experimental results show that alpha-Fe can increase the remanence of Nd-Fe-B/alpha-Fe nanocomposite magnets while decrease the coercivity. The demagnetizing curve indicates that the hard and the soft phases did not coupled very well, even though the remanence was improved. The magnetic properties of Br 8.61 kGs, Hcj 8.59 kOe and (BH)(max) 12.05 MGOe were obtained for Nd-Fe-B/a-Fe nanocomposite magnets with the nominal Fe content of 5 wt.%. It is noted, the exchange coupling was obviously enhanced by a MA process before SPS, and the magnets properties were increased to Br 9.42 kGs and (BH)(max) 14.27 MGOe for Nd-Fe-B/alpha-Fe nanocomposite magnets with the same Fe content.