Spin spring behavior in exchange coupled soft and high-coercivity hard ferromagnets

The magnetization reversal processes in an epitaxial Fe/SM2Co7 structure we re investigated using the magneto-optical indicator film technique. The dep endence of the magnitude and the orientation of the structure average magne tization have been studied on both cycling and rotating the external magnet ic field. Magnetization reversal of the soft ferromagnet was found to proce ed by the formation of exchange springs due to spin winding in both the thi ckness and perpendicular directions as adjacent subdomains with opposite ch irality are created. Experimental data is compared with a theoretical estim ation of the rotational hysteresis loop for a spin system containing a one- dimensional (single chirality) exchange spring.