Uncovering domain morphology in an unconventional magnet with scanning diamond quantum magnetometry
File(s)
Published version
Supporting information
Author(s)
Johnson, Freya
Zemen, Jan
Cohen, Lesley
Knowles, Helena
Cohen, Lesley F
Type
Journal Article
Abstract
Unconventional magnetic materials including non-collinear antiferromagnets, p-wave magnets and altermagnets, are an emerging frontier for quantum spintronics and hybrid quantum devices. Critical to the application of these materials is control over the magnetic domain state, as their unique, symmetry-driven properties vanish in a multi-domain limit. However, the mechanisms governing domain formation in materials with compensated local moments remain poorly understood. In this work, we examine the ferrimagnetic to non-collinear antiferromagnetic phase transition of Mn3NiN using scanning nitrogen-vacancy centre magnetometry. We provide nanoscale mapping of the magnetic domain evolution on cooling and correlate the local stray fields with global magnetometry and anomalous Hall effect measurements. We observe the formation of a disordered, dendritic domain structure whose roughness is quantified using its fractal dimension. The fractal dimension steadily increases on cooling through the transition, saturating at a value of ~ 1.55 in the non-collinear phase, but the domain area distribution does not show any significant changes. We show this behaviour cannot be explained by the balance of demagnetisation energy and domain wall energy, and conclude elastic contributions and defects are a critical factor to explain the domain size.
Date Issued
2026-06-01
Date Acceptance
2026-04-24
Citation
Materials for Quantum Technology, 2026, 6 (2)
ISSN
2633-4356
Publisher
IOP Publishing
Journal / Book Title
Materials for Quantum Technology
Volume
6
Issue
2
Copyright Statement
© 2026 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
License URL
Identifier
10.1088/2633-4356/ae64a0
Subjects
unconventional magnetism
quantum spintronics
scanning nitrogen-vacancy centre magnetometry
magnetic domains
Publication Status
Published
Article Number
ARTN 025201
Date Publish Online
2026-05-13