Micromagnetometry of two-dimensional ferromagnets

M. Kim*, P. Kumaravadivel, J. Birkbeck, W. Kuang, S. G. Xu, D. G. Hopkinson, J. Knolle, P. A. McClarty, A. I. Berdyugin, M. Ben Shalom, R. V. Gorbachev, S. J. Haigh, S. Liu, J. H. Edgar, K. S. Novoselov, I. V. Grigorieva, A. K. Geim

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

117 Scopus citations

Abstract

The study of atomically thin ferromagnetic crystals has led to the discovery of unusual magnetic behaviour and provided insight into the magnetic properties of bulk materials. However, the experimental techniques that have been used to explore ferromagnetism in such materials cannot probe the magnetic field directly. Here, we show that ballistic Hall micromagnetometry can be used to measure the magnetization of individual two-dimensional ferromagnets. Our devices are made by van der Waals assembly in such a way that the investigated ferromagnetic crystal is placed on top of a multi-terminal Hall bar made from encapsulated graphene. We use the micromagnetometry technique to study atomically thin chromium tribromide (CrBr3). We find that the material remains ferromagnetic down to monolayer thickness and exhibits strong out-of-plane anisotropy. We also find that the magnetic response of CrBr3 varies little with the number of layers and its temperature dependence cannot be described by the simple Ising model of two-dimensional ferromagnetism.

Original languageEnglish
Pages (from-to)457-463
Number of pages7
JournalNature Electronics
Volume2
Issue number10
DOIs
StatePublished - 1 Oct 2019
Externally publishedYes

Funding

FundersFunder number
Lloyd's Register Foundation
Graphene NowNANO Doctoral Training Programme
Register Foundation
European Commission
European Research Council
National Sleep Foundation
Seventh Framework Programme319277, 1538127
National Science FoundationCMMI 1538127, 1538127
Engineering and Physical Sciences Research CouncilEP/K005014/1
Horizon 2020 Framework Programme786532, 785219
National Research Foundation of Korea2018R1A6A3A03010943

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