Imaging domain reversal in an ultrathin van der Waals ferromagnet

Abstract

The recent isolation of two-dimensional van der Waals magnetic materials has uncovered rich physics that often differs from the magnetic behaviour of their bulk counterparts. However, the microscopic details of fundamental processes such as the initial magnetization or domain reversal, which govern the magnetic hysteresis, remain largely unknown in the ultrathin limit. Here we employ a widefield nitrogen-vacancy (NV) microscope to directly image these processes in few-layer flakes of magnetic semiconductor vanadium triiodide (VI${}_3$). We observe complete and abrupt switching of most flakes at fields $H_c\approx 0.5-1$ T (at 5 K) independent of thickness down to two atomic layers, with no intermediate partially-reversed state. The coercive field decreases as the temperature approaches the Curie temperature ($T_c\approx 50$ K), however, the switching remains abrupt. We then image the initial magnetization process, which reveals thickness-dependent domain wall depinning fields well below $H_c$. These results point to ultrathin VI${}_3$ being a nucleation-type hard ferromagnet, where the coercive field is set by the anisotropy-limited domain wall nucleation field. This work illustrates the power of widefield NV microscopy to investigate magnetization processes in van der Waals ferromagnets, which could be used to elucidate the origin of the hard ferromagnetic properties of other materials and explore field- and current-driven domain wall dynamics.

arXiv commentincludes SI

References in corpus (26)

• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• The nitrogen-vacancy colour centre in diamond
• Gate-tunable Room-temperature Ferromagnetism in Two-dimensional Fe${}_3$GeTe${}_2$
• Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds
• Current-driven dynamics of chiral ferromagnetic domain walls
• Magnetic 2D materials and heterostructures
• Two-Dimensional Itinerant Ising Ferromagnetism in Atomically thin Fe3GeTe2
• Electrical Control of 2D Magnetism in Bilayer CrI3
• Magnetometry with nitrogen-vacancy defects in diamond
• Controlling magnetism in 2D CrI3 by electrostatic doping
• A robust, scanning quantum system for nanoscale sensing and imaging
• Probing condensed matter physics with magnetometry based on nitrogen-vacancy centres in diamond
• Direct observation of van der Waals stacking dependent interlayer magnetism
• Pressure-controlled interlayer magnetism in atomically thin CrI3
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Hard magnetic properties in nanoflake van der Waals Fe3GeTe2
• Observation of Magnetic Skyrmion Bubbles in a van der Waals ferromagnet Fe3GeTe2
• High sensitivity magnetic imaging using an array of spins in diamond
• Quantum imaging of current flow in graphene
• Ferromagnetic van der Waals crystal VI3
• VI3 - a new layered ferromagnetic semiconductor
• Topological magnetic-spin textures in two-dimensional van der Waals Cr2Ge2Te6
• Bulk properties of van-der-Waals hard ferromagnet VI3
• Laser modulation of superconductivity in a cryogenic widefield nitrogen-vacancy microscope
• Proximity-induced artefacts in magnetic imaging with nitrogen-vacancy ensembles in diamond

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