Influence of FeCo-interlayer thickness on remanence and coercivity in SmCo/FeCo/SmCo triple-layer films

The dependence of reduced remanence (Mr/Ms) and coercivity of Sm/sub 22/Co/sub 78//Fe/sub 65/Co/sub 35//Sm/sub 22/Co/sub 78/ triple-layer films on Fe/sub 65/Co/sub 35/ soft-magnetic interlayer thickness, d, was systematically investigated. All the hysteresis loops of the triple-layer films exhibit a single-phase behavior, reflecting a strong exchange coupling between soft- and hard-magnetic phases. Mr/Ms shows a monotonic increase with increasing the Fe/sub 65/Co/sub 35/ thickness, d, and the coercivity exists a peak with increasing d. From the plot of the interaction-based deviation parameter /spl Delta/M (H) of two principle remanence curves (isothermal remanence magnetization and dc-demagnetization remanence) versus applied field, H, a negative interaction profile was observed, indicating a negligible inter-granular exchange coupling within hard-magnetic grains.