DYNAMIC HYSTERESIS LOOP OF A FERROMAGNETIC LAYER: EFFECT OF THE HIGH SECOND ORDER OF THE ANISOTROPY CONSTANT.

Dynamic magnetization reversal measurements at room temperature have been performed by magneto-optical effect on Au/Co/Au sandwiches with perpendicular anisotropy. Domain wall displacement and domain nucleation regimes govern the magnetization reversal at low and high-applied field sweep rates, respectively. The transition between the two regimes occurs at 200 Oe/s.