Domain wall dynamics near the compensation point in amorphous magnetic films

We have investigated the dynamics of an isolated straight domain wall near the compensation temperature in rare-earth transition metal amorphous magnetic films. Wall velocities up to 3.5 × 10⁴cm/sec are observed for applied field up to 550 Oe. Nonlinear dependence of the wall velocity on drive field is observed. The wall mobility in low drive region is very sensitive to the temperature and/or to the coercive force of the film. In high drive region, remarkable transient behavior, that is, very high instantaneous velocity just after the onset of wall motion and velocity break down are detected. Some films have remarkable orthorhombic anisotropy, and in these films the domain wall velocity depends on the direction of the wall motion with respect to the in-plane easy axis of the film. Change of the wall velocity by Permalloy overlay is also observed.