Pinning and hysteresis in the field dependent diameter evolution of skyrmions in Pt/Co/Ir superlattice stacks

Zeissler, K. et al. (2017) Pinning and hysteresis in the field dependent diameter evolution of skyrmions in Pt/Co/Ir superlattice stacks. Scientific Reports, 7, 15125. (doi: 10.1038/s41598-017-15262-3) (PMID:29123144) (PMCID:PMC5680206)

Abstract

We have imaged Néel skyrmion bubbles in perpendicularly magnetised polycrystalline multilayers patterned into 1 µm diameter dots, using scanning transmission x-ray microscopy. The skyrmion bubbles can be nucleated by the application of an external magnetic field and are stable at zero field with a diameter of 260 nm. Applying an out of plane field that opposes the magnetisation of the skyrmion bubble core moment applies pressure to the bubble and gradually compresses it to a diameter of approximately 100 nm. On removing the field the skyrmion bubble returns to its original diameter via a hysteretic pathway where most of the expansion occurs in a single abrupt step. This contradicts analytical models of homogeneous materials in which the skyrmion compression and expansion are reversible. Micromagnetic simulations incorporating disorder can explain this behaviour using an effective thickness modulation between 10 nm grains.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McVitie, Professor Stephen and Fallon, Kayla and McFadzean, Dr Sam
• Authors: Zeissler, K., Mruczkiewicz, M., Finizio, S., Raabe, J., Shepley, P. M., Sadovnikov, A. V., Nikitov, S. A., Fallon, K., McFadzean, S., McVitie, S., Moore, T. A., Burnell, G., and Marrows, C. H.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Scientific Reports 7(1):15125
• Publisher Policy: Reproduced under a Creative Commons License