New type of γ1-FePt/Fe2B exchange-coupled spring magnet obtained from Fe56.25Pt18.75B25 amorphous alloy

The best hard magnetic properties observed for the Fe56.25Pt18.75B25 amorphous alloy after annealing are attributed to the exchange coupling between the nanoscale hard γ1-FePt, soft Fe2B and remaining amorphous magnetic phases. The existence of the remaining amorphous phase is shown to be important in the maintenance of a fine nanocomposite structure.