Bias-field dependence of the spatiotemporal evolution of magnetization reversal in a mesoscopic Ni80Fe20 element - art. no. 144418

Ultrafast magnetization reversal dynamics in a Ni80Fe20 microstructure (10 mum by 2 mum in size and 15 nm thick) is studied using time-resolved scanni ng Kerr microscopy. The temporal evolution of the magnetization reversal re veals a dramatic reduction in switching time, when a steady transverse bias ing field accompanies the pulsed longitudinal switching field applied to th e sample. According to the analysis of time-domain images, it is concluded that the abrupt change of the switching time is due to a change in the magn etization reversal mode: the nucleation dominant reversal process is replac ed by quasicoherent domain wall motion in the presence of an additional tra nsverse biasing field. The experimental data are compared to results from m icromagnetic modeling, based on the Landau-Liftshitz-Gilbert equation. The observed distinct magnetization reversal behaviors dependent on applied fie ld conditions are well reproduced in the simulations.