Interior and edge magnetization in thin exfoliated CrGeTe3 films

Abstract

CrGeTe3 (CGT) is a semiconducting vdW ferromagnet shown to possess magnetism down to a two-layer thick sample. Although CGT is one of the leading candidates for spintronics devices, a comprehensive analysis of CGT thickness dependent magnetization is currently lacking. In this work, we employ scanning SQUID-on-tip (SOT) microscopy to resolve the magnetic properties of exfoliated CGT flakes at 4.2 K. Combining transport measurements of CGT/NbSe2 samples with SOT images, we present the magnetic texture and hysteretic magnetism of CGT, thereby matching the global behavior of CGT to the domain structure extracted from local SOT magnetic imaging. Using this method, we provide a thickness dependent magnetization state diagram of bare CGT films. No zero-field magnetic memory was found for films thicker than 10 nm and hard ferromagnetism was found below that critical thickness. Using scanning SOT microscopy, we identify a unique edge magnetism, contrasting the results attained in the CGT interior.

Main text: 15 pages, 5 figures. Supplementary information: 9 pages, 10 figures. Supplementary videos: 5

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• Boron nitride substrates for high-quality graphene electronics
• Graphene Spintronics
• Van der Waals heterostructures for spintronics and opto-spintronics
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures
• Probing Magnetism in Insulating Cr2Ge2Te6 by Induced Anomalous Hall Effect in Pt
• SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging
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Cited by in corpus (4)

• Nano-Patterned Magnetic Edges in CrGeTe3 for Quasi 1-D Spintronic Devices
• Scanning SQUID-on-tip microscope in a top-loading cryogen-free dilution refrigerator
• Sizable suppression of magnon Hall effect by magnon damping in Cr${}_2$Ge${}_2$Te${}_6$
• Gate-tunable anomalous Hall effect in stacked van der Waals ferromagnetic insulator - topological insulator heterostructures