# Observation of stable Neel skyrmions in Co/Pd multilayers with Lorentz transmission electron microscopy

## TL;DR

This study demonstrates the direct imaging of stable Neel skyrmions at room temperature in Co/Pd multilayers using Lorentz transmission electron microscopy, revealing detailed internal spin structures without external stabilizing fields.

## Contribution

It provides the first direct visualization and internal spin structure mapping of Neel skyrmions in thick multilayers at room temperature using Lorentz TEM.

## Key findings

- Neel skyrmions observed at room temperature in Co/Pd multilayers.
- Internal spin structure mapped with phase retrieval techniques.
- Skyrmions stabilized without external out-of-plane magnetic fields.

## Abstract

Neel skyrmions are of high interest due to their potential applications in a variety of spintronic devices, currently accessible in ultrathin heavy metal/ferromagnetic bilayers and multilayers with a strong Dzyaloshinskii-Moriya interaction. Here we report on the direct imaging of chiral spin structures including skyrmions in an exchange coupled Co/Pd multilayer at room temperature with Lorentz transmission electron microscopy, a high resolution technique previously suggested to exhibit no Neel skyrmion contrast. Phase retrieval methods allow us to map the internal spin structure of the skyrmion core, identifying a 25 nm central region of uniform magnetization followed by a larger region characterized by rotation from in- to out-of-plane. The formation and resolution of the internal spin structure of room temperature skyrmions without a stabilizing out-of-plane field in thick magnetic multilayers opens up a new set of tools and materials to study the physics and device applications associated with chiral ordering and skyrmions.

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Source: https://tomesphere.com/paper/1702.00113