Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature

• Published in: Nature nanotechnology Vol. 11; no. 5; pp. 444 - 448
• Main Authors: Moreau-Luchaire, C., Moutafis, C., Reyren, N., Sampaio, J., Vaz, C. A. F., Van Horne, N., Bouzehouane, K., Garcia, K., Deranlot, C., Warnicke, P., Wohlhüter, P., George, J.-M., Weigand, M., Raabe, J., Cros, V., Fert, A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.05.2016; Nature Publishing Group
• Subjects: 639/301; 639/766/119/1001; Additives; Cobalt; Data storage; Heavy metals; Hypothetical particles; Magnetic fields; Materials Science; Multilayers; Nanostructure; Nanotechnology; Nanotechnology and Microengineering; Particle theory; Surface layer; Texture; Thin films; France; Switzerland
• ISSN: 1748-3387; 1748-3395
• DOI: 10.1038/nnano.2015.313

Facing the ever-growing demand for data storage will most probably require a new paradigm. Nanoscale magnetic skyrmions are anticipated to solve this issue as they are arguably the smallest spin textures in magnetic thin films in nature. We designed cobalt-based multilayered thin films in which the cobalt layer is sandwiched between two heavy metals and so provides additive interfacial Dzyaloshinskii–Moriya interactions (DMIs), which reach a value close to 2 mJ m –2 in the case of the Ir|Co|Pt asymmetric multilayers. Using a magnetization-sensitive scanning X-ray transmission microscopy technique, we imaged small magnetic domains at very low fields in these multilayers. The study of their behaviour in a perpendicular magnetic field allows us to conclude that they are actually magnetic skyrmions stabilized by the large DMI. This discovery of stable sub-100 nm individual skyrmions at room temperature in a technologically relevant material opens the way for device applications in the near future. Magnetic skyrmions can be stabilized at room temperature in cobalt layers sandwiched between heavy metal layers due to engineering of the interfacial Dzyaloshinskii–Moriya interaction.