Inhomogeneous Spin Reorientation Transition (SRT) in Giant Magnetostrictive TbCo$_2$/FeCo Multilayers

Inhomogeneous magnetization states occurring when inducing the spin reorientation transition (SRT) in uniaxial giant magnetostrictive thin films are studied in detail. Theoretical background of SRT in the layers is given and the limitations of the single domain model are explained. The results of the magneto-optical measurements are then given and discussed. We showed that the behavior of devices using the SRT can be explained by the creation of magnetic domains, if the applied magnetic field is perfectly aligned with the hard axis. Magneto-optic evidence of the hyper sensitivity near the SRT is also given