We investigate the anisotropy of magnetic reversal and current-driven domainwall motion in annealed Ga_0.95Mn_0.05As thin films and Hall bar devices withperpendicular magnetic anisotropy. Hall bars with current direction along the[110] and [1-10] crystallographic axes are studied. The [110] device showslarger coercive field than the [1-10] device. Strong anisotropy is observedduring magnetic reversal between [110] and [1-10] directions. A power lawdependence is found for both devices between the critical current (JC) and themagnetization (M), with J_C is proportional to M^2.6. The domain wall motion isstrongly influenced by the presence of local pinning centres.
展开▼
