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arXiv · 1811.02012

Lorentz TEM investigation of chiral spin textures and N\'eel Skyrmions in asymmetric [Pt/(Co/Ni)$_M$/Ir]$_N$ multi-layer thin films

Maxwell Li·Derek Lau·Marc De Graef·Vincent Sokalski
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Abstract

We examine magnetic domain patterns in symmetric [Co/Ni]$_M$ and asymmetric [Pt/(Co/Ni)$_M$/Ir]$_N$ multi-layers using Fresnel mode Lorentz transmission electron microscopy (LTEM). In the symmetric multi-layer, where the Dzyaloshinskii-Moriya Interaction is expected to be zero, we observe purely Bloch type domain walls with no preferred chirality. In the asymmetric multi-layers, where significant interfacial DMI is present, we observe domain patterns with chiral N\'eel domain walls, which evolve into sub-100nm isolated N\'eel Skyrmions with the application of a perpendicular field. The impact of layer thickness and film stack on interfacial magnetic properties is discussed in the context of developing a tunable multi-layer system for future spintronic applications.

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Maxwell Li, Derek Lau, Marc De Graef, Vincent Sokalski. 2018-11-05. Lorentz TEM investigation of chiral spin textures and N\'eel Skyrmions in asymmetric [Pt/(Co/Ni)$_M$/Ir]$_N$ multi-layer thin films. https://doi.org/10.1103/physrevmaterials.3.064409

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