Micromagnetic modeling of magnetic domain walls in curved cylindrical nanotubes and nanowires

Skoric, L., Donnelly, C., Abert, C., Hierro-Rodriguez, A., Suess, D. and Fernández-Pacheco, A. (2021) Micromagnetic modeling of magnetic domain walls in curved cylindrical nanotubes and nanowires. Applied Physics Letters, 118(24), 242403. (doi: 10.1063/5.0050872)

Abstract

We investigate the effect of curvature on the energy and stability of domain wall configurations in curved cylindrical nanotubes and nanowires. We use micromagnetic simulations to calculate the phase diagram for the transverse wall (TW) and vortex wall (VW) states in tubes, finding the lower energy configuration and the metastability region where both types of walls can exist. The introduction of curvature shifts the range for which the TW is the ground state domain wall to higher diameters and increases the range of metastability. We interpret this behavior to be primarily due to the curvature-induced effective Dzyaloshinskii–Moriya term in the exchange energy. Furthermore, we demonstrate qualitatively the same behavior in solid cylindrical nanowires. Comparing both tubes and wires, we observe how while in tubes curvature tends to suppress the transformation from the TW to VW, in wires it promotes the transformation of the VW containing the Bloch point into the TW. These findings have important implications in the fundamental understanding of domain walls in 3D geometries and the design of future domain wall devices.

• Item Type: Articles
• Additional Information: This work was supported by EPSRC Cambridge NanoDTC No. EP/L015978/1 and the Winton Program for the Physics of Sustainability. L. Skoric acknowledges the support from St Johns College of the University of Cambridge. C. Donnelly was supported by the Leverhulme Trust (No. ECF-2018-016), the Isaac Newton Trust (No. 18-08), and the L’Oreal-UNESCO UK and Ireland Fellowship For Women In Science. A. Hierro-Rodriguez acknowledges support from Spanish AEI under Project Reference No. PID2019-104604RB/AEI/10.13039/501100011033. The authors acknowledge the University of Vienna research platform MMM Mathematics-Magnetism-Materials, and FWF Project No. I 4917.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hierro Rodriguez, Dr Aurelio and Fernandez-Pacheco, Dr Amalio
• Authors: Skoric, L., Donnelly, C., Abert, C., Hierro-Rodriguez, A., Suess, D., and Fernández-Pacheco, A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Applied Physics Letters
• Publisher: AIP Publishing
• ISSN: 0003-6951
• ISSN (Online): 1077-3118
• Published Online: 17 June 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Applied Physics Letters 118(24): 242403
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.17863/CAM.70776