Mechanically alloyed hard magnetic materials

Recent developments in the synthesis of hard magnetic materials by mechanical alloying are reviewed. In rare earth-transition metal compounds the nanocrystalline structure developed by mechanical alloying and heat treatment results in ultra-high coercivity and isotropic behaviour associated with random grain alignment. Mechanically alloyed two phase exchange-coupled materials exhibit remanence enhancement, and the reversible and irreversible magnetisation behaviour of this novel class of permanent magnet is also discussed.