Tb nanoparticles doped Nd–Fe–B sintered permanent magnet with enhanced coercivity

Abstract

The microstructure and magnetic properties were studied for the sintered Nd–Fe–B permanent magnet doped with terbium (Tb) nanoparticles. Investigation shows that Tb is enriched as Tb2Fe14B and/or (Nd,Tb)2Fe14B phase in the surface region of the Nd2Fe14B matrix grains indicated by the remarkable enhancement in the magnetocrystalline anisotropy field of the magnet. Furthermore, the Tb-rich grain surface region with high crystal anisotropy increases the nucleation field of reverse domains in the demagnetization process. As a result, the magnet doped with a small amount of Tb nanoparticles possesses enhanced coercivity without sacrificing its magnetization.