Sm-Co hard magnetic nanoparticles prepared by surfactant-assisted ball milling.

Hard magnetic nanoparticles based on the Sm(2)Co(17) and SmCo(5) systems have been successfully produced using a surfactant-assisted ball milling technique. A size-selection process has been developed to obtain nanoparticles of different sizes with narrow size distribution. Significant room-temperature coercivity up to 3.1 kOe has been achieved with the Sm(2)Co(17)-based nanoparticles of an average size of 23 nm. It has been found that surfactants play multifold roles in the processing.