Nanocomposite (Nd,Dy)(2)Fe14B/alpha-Fe magnetic materials coupled by exchange

International audienceThe structural and magnetic properties of (Nd0.92Dy0.08)2Fe14B/alfa-Fe nanocomposite obtained by mechanical milling and subsequent annealing have been investigated. The structural evolution of the sample was followed versus the milling and annealing conditions by X-ray diffraction. The width of the diffraction peaks of the magnetic phase was found to increase with milling time and the peaks almost disappeared after 12 hours of milling. The characteristic diffraction peaks of the (Nd0.92Dy0.08)2Fe14B phase are restored during subsequent heat treatment. The coercive field, remanent magnetization and the degree of the exchange coupling between the hard magnetic gains and the soft grains are dependent on the milling time and the annealing conditions. The exchange coupling between the soft magnetic alfa -Fe, and the hard magnetic (Nd,Dy)2Fe14B-type phase is analysed