Domain wall structure in magnetic bilayers with perpendicular anisotropy

TL;DR

This study investigates the detailed structure of magnetic domain walls in bilayer systems with perpendicular magnetization, revealing a transition from Bloch to Ne9el walls due to interlayer coupling, supported by microscopy and micromagnetic calculations.

Contribution

It provides high-resolution experimental insights into domain wall structures in magnetic bilayers and confirms the transition from Bloch to Ne9el walls through quantitative micromagnetic modeling.

Findings

Classical Bloch walls transform into Ne9el walls in bilayers

High spatial accuracy microscopy reveals detailed wall structure

Quantitative agreement with micromagnetic simulations

Abstract

We study the magnetic domain wall structure in magnetic bilayers (two ultrathin ferromagnetic layers separated by a non magnetic spacer) with perpendicular magnetization. Combining magnetic force and ballistic electron emission microscopies, we are able to reveal the details of the magnetic structure of the wall with a high spatial accuracy. In these layers, we show that the classical Bloch wall observed in single layers transforms into superposed N\'eel walls due to the magnetic coupling between the ferromagnetic layers. Quantitative agreement with micromagnetic calculations is achieved.