Time-resolved measurements of field-driven domain wall motion in a submicron strip with perpendicular magnetic anisotropy

Abstract

The motion of domain walls (DWs), driven by magnetic field and spanning almost eight orders of magnitude in velocity, has been studied in a submicron-wide strip of Co/Pt with perpendicular magnetic anisotropy. A scanning magneto-optic Kerr effect (MOKE) system is used to conduct time-resolved measurements of DW dynamics in both the thermally activated and viscous flow regimes. MOKE signal transients in the thermally activated regime reveal distributions of stochastic DW propagation events. Transients in the viscous flow regime show deterministic DW motion with velocities ∼20 m/s. The transition between the two dynamic regimes is observed as the relationship between the DW velocity and the driving magnetic field changes from exponential to linear.