Magnetic and structural behaviour of (Nd,Dy)2Fe14B/α-Fe nanocomposites obtained by mechanical milling and annealing

(Nd 0.92 Dy 00.8 ) 2 Fe 14 B/a-Fe hard/soft magnetic nanocomposite have been obtained by mechanical milling in a high-energy planetary mill and subsequent annealing under vacuum. The influence of the milling and annealing conditions (temperature and time) on the structural and magnetic properties of (Nd 0.92 Dy 0.08 )2Fe14B/a-Fe nanocomposite have been investigated. Annealing at 550°C restores the magnetic features of the Nd 2 Fe 14 B - type phase. The coercive field, remanent magnetization and the degree of the exchange coupling between the hard magnetic grains and the soft grains are strongly dependent on the milling time and the annealing conditions.