Superferromagnetism and domain-wall topologies in artificial 'pinwheel' spin ice

Li, Y. et al. (2019) Superferromagnetism and domain-wall topologies in artificial 'pinwheel' spin ice. ACS Nano, 13(2), pp. 2213-2222. (doi:10.1021/acsnano.8b08884) (PMID:30588800)

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Abstract

For over ten years, arrays of interacting single-domain nanomagnets, referred to as artificial spin ices, have been engineered with the aim to study frustration in model spin systems. Here, we use Fresnel imaging to study the reversal process in ‘pinwheel’ artificial spin ice, a modified square ASI structure obtained by rotating each island by some angle about its midpoint. Our results demonstrate that a simple 45° rotation changes the magnetic ordering from antiferromagnetic to ferromagnetic, creating a superferromagnet which exhibits mesoscopic domain growth mediated by domain wall nucleation and coherent domain propagation. We observe several domain-wall configurations, most of which are direct analogues to those seen in continuous ferromagnetic films. However, charged walls also appear due to the geometric constraints of the system. Changing the orientation of the external magnetic field allows control of the nature of the spin reversal with the emergence of either 1-D or 2-D avalanches. This property of pinwheel ASI could be employed to tune devices based on magnetotransport phenomena such as Hall circuits.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Macauley, Mr Gavin and Paterson, Dr Gary and Ferguson, Mr Ciaran and Li, Miss Yue and McVitie, Professor Stephen and Stamps, Professor Robert and Macedo, Dr Rair and MacLaren, Dr Donald
Authors: Li, Y., Paterson, G. W., Macauley, G. M., Nascimento, F. S., Ferguson, C., Morley, S. A., Rosamond, M. C., Linfield, E. H., MacLaren, D. A., Macedo, R., Marrows, C. H., McVitie, S., and Stamps, R. L.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:ACS Nano
Publisher:American Chemical Society
ISSN:1936-0851
ISSN (Online):1936-086X
Published Online:27 December 2018
Copyright Holders:Copyright © 2018 American Chemical Society
First Published:First published in ACS Nano 13:2213-2222
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
629961Artificial spin ice: designer matter far from equilibriumRobert StampsEngineering and Physical Sciences Research Council (EPSRC)EP/L002922/1S&E P&A - PHYSICS & ASTRONOMY
683531Consortium for advanced materials based on spin chiralityRobert StampsEngineering and Physical Sciences Research Council (EPSRC)EP/M024423/1S&E P&A - PHYSICS & ASTRONOMY