Preparation of Nd–Fe–B nanoparticles by surfactant-assisted ball milling technique.

Nd–Fe–B nanoparticles have been obtained by using surfactant-assisted ball milling and subsequent size-selection technique. Structural analyses show that nanoparticles with two particle sizes around 10 and 100 nm were obtained. The partially amorphous Nd–Fe–B nanoparticles give their room-temperature coercivities around 0.1 and 1.5 kOe for the small and large nanoparticles, respectively. As the temperature decreases to 200 K, the coercive force of the large nanoparticles increases by 50% due to the enhancement of the magnetocrystalline anisotropy of the Nd2Fe14B phase in the particles. [ABSTRACT FROM AUTHOR]