Transition from the thermal activation process to the viscous process in magnetization reversal behavior of the Co/Pd multilayer

Abstract

We have investigated the transition from thermal activation process to viscous process in magnetization reversal behavior of the Co/Pd multilayer from the determination of the wall-motion speed and the nucleation rate via time-resolved domain observation. Interestingly, we find that the field dependencies of two activation volumes in the thermal activation regime are different from each other, which reveals that the wall-motion and nucleation experience completely different interactions. We also find that the wall-mobility in the viscous regime is much smaller than a typical value for the sandwiched Co films, which implies that the Co/Pd interfaces substantially contribute to the dynamic dissipation. (C) 2004 American Institute of Physics.