360 degree domain wall generation in the soft layer of magnetic tunnel junctions

TL;DR

This study uses advanced microscopy and simulations to demonstrate the formation and stabilization of 360-degree domain walls in the soft layer of magnetic tunnel junctions, revealing insights into magnetic domain behavior.

Contribution

The paper introduces experimental and numerical evidence for the stabilization of 360-degree domain walls in NiFe layers of magnetic tunnel junctions, highlighting the role of dipolar coupling.

Findings

360-degree domain walls can be stabilized in NiFe layers

Dipolar coupling influences domain wall formation

Microscopy and simulations agree on domain wall origin

Abstract

High spatial resolution X-ray photo-emission electron microscopy technique has been used to study the influence of the dipolar coupling taking place between the NiFe and the Co ferromagnetic electrodes of micron sized, elliptical shaped magnetic tunnel junctions. The chemical selectivity of this technique allows to observe independently the magnetic domain structure in each ferromagnetic electrode. The combination of this powerful imaging technique with micromagnetic simulations allows to evidence that a 360 degree domain wall can be stabilized in the NiFe soft layer. In this letter, we discuss the origin and the formation conditions of those 360 degree domain walls evidenced experimentally and numerically.