Above-room-temperature ferromagnetism in ultrathin van der Waals magnet

Abstract

Two-dimensional (2D) magnetic van der Waals materials provide a powerful platform for studying fundamental physics of low-dimensional magnetism, engineering novel magnetic phases, and enabling ultrathin and highly tunable spintronic devices. To realize high quality and practical devices for such applications, there is a critical need for robust 2D magnets with ordering temperatures above room temperature that can be created via exfoliation. Here the study of exfoliated flakes of cobalt substituted Fe5GeTe2 (CFGT) exhibiting magnetism above room temperature is reported. Via quantum magnetic imaging with nitrogen-vacancy centers in diamond, ferromagnetism at room temperature was observed in CFGT flakes as thin as 16 nm. This corresponds to one of the thinnest room-temperature 2D magnet flakes exfoliated from robust single crystals, reaching a thickness relevant to practical spintronic applications. The Curie temperature Tc of CFGT ranges from 310 K in the thinnest flake studied to 328 K in the bulk. To investigate the prospect of high-temperature monolayer ferromagnetism, Monte Carlo calculations were performed which predicted a high value of Tc ~270 K in CFGT monolayers. Pathways towards further enhancing monolayer Tc are discussed. These results support CFGT as a promising platform to realize high-quality room-temperature 2D magnet devices.

References in corpus (37)

• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Gate-tunable Room-temperature Ferromagnetism in Two-dimensional Fe${}_3$GeTe${}_2$
• Magnetic 2D materials and heterostructures
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Two-Dimensional Itinerant Ising Ferromagnetism in Atomically thin Fe3GeTe2
• Atomistic spin model simulations of magnetic nanomaterials
• Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit
• Probing condensed matter physics with magnetometry based on nitrogen-vacancy centres in diamond
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Roadmap on Spin-Wave Computing
• Imaging viscous flow of the Dirac fluid in graphene
• Room temperature 2D ferromagnetism in few-layered 1$T$-CrTe${}_2$
• Skyrmions in the moiré of van der Waals 2D magnets
• Highly efficient spin-orbit torque and switching of layered ferromagnet Fe3GeTe2
• Intrinsic 2D-XY ferromagnetism in a van der Waals monolayer
• Gigahertz frequency antiferromagnetic resonance and strong magnon-magnon coupling in the layered crystal CrCl3
• Wide Field Imaging of van der Waals Ferromagnet Fe3GeTe2 by Spin Defects in Hexagonal Boron Nitride
• Twist engineering of the two-dimensional magnetism in double bilayer chromium triiodide homostructures
• Physical properties and thermal stability of Fe5GeTe2 single crystals
• Ferromagnetism in 2D Vanadium Diselenide
• Tunable magnetic properties in van der Waals crystals (Fe${}_{1-x}$Co${}_x$)${}_5$GeTe${}_2$
• Tuning Magnetic Order in the van der Waals Metal Fe5GeTe2 by Cobalt Substitution
• Large-scale epitaxy of two-dimensional van der Waals room-temperature ferromagnet Fe5GeTe2
• Imaging domain reversal in an ultrathin van der Waals ferromagnet
• Magnetic imaging with spin defects in hexagonal boron nitride
• Thickness-dependent magnetic order in CrI${}_3$ single crystals
• Characterization of room-temperature in-plane magnetization in thin flakes of CrTe${}_2$ with a single spin magnetometer
• Theory and simulations of critical temperatures in CrI3 and other 2D materials: Easy-axis magnetic order and easy-plane Kosterlitz-Thouless transitions
• Critical behavior of ferromagnets CrI3, CrBr3, CrGeTe3, and anti-ferromagnet FeCl2: a detailed first-principles study
• Observation of Superconductivity Induced Ferromagnetism in an Fe-Chalcogenide Superconductor
• Self-hybridization and tunable magnon-magnon coupling in van der Waals synthetic magnets
• $ab$-$initio$ Approaches for Low-Energy Spin Hamiltonians
• Revealing room temperature ferromagnetism in exfoliated Fe${}_5$GeTe${}_2$ flakes with quantum magnetic imaging
• Spin-torque oscillation in a magnetic insulator probed by a single-spin sensor
• Antiferromagnetic order in Co-doped Fe${}_5$GeTe${}_2$ probed by resonant magnetic x-ray scattering
• Magnetic imaging and statistical analysis of the metamagnetic phase transition of FeRh with electron spins in diamond

Cited by in corpus (8)

• Deterministic and non-volatile switching of all-van der Waals spin-orbit torque system above room temperature without external magnetic fields
• Progress and Prospects in Two-Dimensional Magnetism of van der Waals Materials
• Nitrogen-vacancy magnetometry of CrSBr by diamond membrane transfer
• Flat bands and magnetism in $\mathbf{F}{\mathbf{e}}_4\mathbf{GeT}{\mathbf{e}}_2$ and $\mathbf{F}{\mathbf{e}}_5\mathbf{GeT}{\mathbf{e}}_2$ due to bipartite crystal lattices
• Tuning magnetic anisotropy in Fe${}_5$GeTe${}_2$ monolayer through doping and strain
• Nearly-room-temperature ferromagnetism and tunable anomalous Hall effect in atomically thin Fe4CoGeTe2
• Magnetic excitations and absence of charge order in the van der Waals ferromagnet Fe${}_{4.75}$GeTe${}_2$
• Quantum Imaging of Ferromagnetic van der Waals Magnetic Domain Structures at Ambient Conditions