Magnetic properties of nanostructured SmCo/FeCo multilayers

The dependence of reduced remanence (M-r/M-s) and coercivity of Sm22Co78/Fe 65Co35 bilayer and Sm22Co78/Fe65Co35/Sm22Co78 triple-layer films on Fe65Co3 5 soft-magnetic layer thickness d, was systematically investigated. All the hysteresis loops of the films exhibited a single-phase behavior, reflectin g a strong exchange coupling between soft- and hard-magnetic phase. M-r/M-s , showed a monotonic increase with increasing Fe65Co35 thickness d, and the coercivity would show a peak with increasing d. From the plot of Delta M v ersus applied field H, it is shown that the positive profile decreases and the negative interaction profile increases with the increase of interfaces between soft- and hard-layers.