H. Forster, T. Schrefl..., Micromagnetic simulation of... page 1 Micromagnetic simulation of domain wall motion in magnetic nano-wires

Abstract. The magnetization reversal process of magnetic nano-wires was investigated using a moving mesh finite element method. The nucleation and expansion of reversed domains is calculated solving the Gilbert equation of motion. For a wire diameter of d = 20 nm either a transverse wall or a vortex wall is formed, depending on the strength of the initial applied field. Once a reversed domain is nucle-ated, the wall configuration remains the same during the complete reversal process. The vortex wall moves faster than the transverse wall. The domain wall velocities are in the order of 300 m/s to 800 m/s for an external field in the range from 300 kA/m to 600 kA/m for a Gilbert damping constant α = 1. The domain wall velocity increases with increasing wire diameter and decreasing damping constant, reach-ing 2000 m/s for d = 40 nm, α = 0.05, and an applied field of 250 kA/m