Exchange-spring behavior of hard/soft magnetic multilayers: optimization study of the nanostructure

We investigate the magnetization reversal process in two-phase hard/soft (h /s) magnetic multilayers with exchange-spring behavior using a mean-field a pproach to determine the equilibrium configuration. Starting from a trilaye r made of 50h/100s/50h layers, we separately consider the effect of increas ing nanostructuration (while maintaining constant the overall h/s ratio) an d decreasing the thickness of the hard phase (while keeping constant that o f the soft phase) on the maximum energy product (BH)(max). In this way, the optimal composition for the multilayer exchange-spring magnet can be deter mined. (C) 2000 Elsevier Science B.V. All rights reserved.