Superferromagnetism and Domain-Wall Topologies in Artificial "Pinwheel" Spin Ice

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 one- or two-dimensional avalanches. This property of pinwheel ASI could be employed to tune devices based on magnetotransport phenomena such as Hall circuits.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:13

Enthalten in:

ACS nano - 13(2019), 2 vom: 26. Feb., Seite 2213-2222

Sprache:

Englisch

Beteiligte Personen:

Li, Yue [VerfasserIn]
Paterson, Gary W [VerfasserIn]
Macauley, Gavin M [VerfasserIn]
Nascimento, Fabio S [VerfasserIn]
Ferguson, Ciaran [VerfasserIn]
Morley, Sophie A [VerfasserIn]
Rosamond, Mark C [VerfasserIn]
Linfield, Edmund H [VerfasserIn]
MacLaren, Donald A [VerfasserIn]
Macêdo, Rair [VerfasserIn]
Marrows, Christopher H [VerfasserIn]
McVitie, Stephen [VerfasserIn]
Stamps, Robert L [VerfasserIn]

Links:

Volltext

Themen:

Artificial spin ice
Journal Article
Lorentz transmission electron microscopy
Magnetization process
Mesoscopic domain wall
Superferromagnetism

Anmerkungen:

Date Revised 20.11.2019

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1021/acsnano.8b08884

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM292180802