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

Hard magnetic nanoparticles based on the Sm2Co17 and SmCo5 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 Sm2Co17-based nanoparticles of an average size of 23 nm. It has been found that surfactants play multifold roles in the processing.