Mechanisms of the ultrafast magnetization switching in bistable amorphous microwires

Two magnetization reversal regimes were found in magnetically bistable Fe-rich microwires. The first one, exhibiting an almost linear dependence of the domain wall velocity v on magnetic field H reaching 1.7 km/s, is related to single DW propagation. The second essentially nonlinear regime is observed when H exceeds some critical magnetic field, H-N, determined by the microwire in homogeneities. At H > H-N, new reverse domains can be nucleated, and consequently a tandem remagnetization mechanism can be realized. Ultrafast magnetization switching through additional nucleation centers created artificially can be applied in spintronic devices for enhancing their performance. (C) 2009 American Institute of Physics. [doi:10.1063/1.3256121]