Domain Nucleation and Annihilation in Uniformly Magnetized State under Current Pulses in Narrow Ferromagnetic Wires

TL;DR

This paper studies how current pulses induce magnetization changes in narrow ferromagnetic wires, revealing vortex dynamics as a key factor in magnetization reversal, using advanced microscopy techniques.

Contribution

It provides new insights into current-driven magnetization dynamics and the role of vortex behavior in magnetic state transformations in narrow wires.

Findings

Current pulses can induce various magnetic states, including reversed domains.

Vortex dynamics are crucial in triggering magnetization reversal.

Magnetic state transformations occur below the Curie temperature.

Abstract

We investigate the current-driven magnetization dynamics in narrow Permalloy wires by means of Lorentz microscopy and electron holography. Current pulses are found to transform the magnetic structure in the uniformly magnetized state below the Curie temperature. A variety of magnetic states including reversed magnetic domains are randomly obtained in low probability. The dynamics of vortices found in most of observed magnetic states seems to play a key role in triggering the magnetization reversal.