Controllable switch of magnetic vortices in polyhedral iron nanoflakes
Source abstract
Abstract
The discovery of magnetism in ultrathin crystals opens up opportunities for exploring new states of matter and developing next-generation spintronic devices. It is thus crucial to carry out a thorough understanding of microscopic magnetic properties in ultrathin crystals. Here, we systematically investigate magnetic properties in chemical-vapor-deposition-grown iron nanoflakes via in situ Lorentz transmission electron microscopy and magnetic force microscopy. Our results reveal robust room-temperature ferromagnetism with vortex ground states, compared with conventional domain walls, in samples of polyhedral shapes. We further demonstrate that these vortices can be switched in a controllable manner with an external magnetic field. Micromagnetic simulations suggest that these behaviors can be explained by the competition among Heisenberg exchange, anisotropy, and demagnetizing energies. These findings provide guidelines for the design of magnetic and spintronic devices using ultrathin magnetic crystals.
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Research context
OpenAlex topics: Magnetic properties of thin films · Metallic Glasses and Amorphous Alloys · Chemical and Physical Properties of Materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Spin-X Institute, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, South China University of Technology 1 , Guangzhou 511442,
School of Physics and Optoelectronics, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology 2 , Guangzhou 511442,
Center for Electron Microscopy, South China University of Technology 3 , Guangzhou 511442,
Funding
National Key Research and Development Program of China · National Natural Science Fund · GJYC Program of Guangzhou · Guangzhou Basic and Applied Basis Research Foundation · Guangdong Provincial Quantum Science Strategic Initiative · Xiaomi Young Talents Program
References (36)
Show source-provided references
1. Ferromagnetism in 2D vanadium diselenide10.1021/acsnano.1c05232 ↗
2. Gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe210.1038/s41586-018-0626-9 ↗
3. Electrical control of 2D magnetism in bilayer CrI310.1038/s41565-018-0121-3 ↗
4. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit10.1038/nature22391 ↗
5. 2D air-stable nonlayered ferrimagnetic FeCr2S4 crystals synthesized via chemical vapor deposition10.1002/adma.202401338 ↗
6. Controllable synthesis of magnetic 2D non-layered cobalt sulfide nanocrystals using chemical vapor deposition10.1002/smll.202406202 ↗
7. Tunable room-temperature magnetic skyrmions in Ir/Fe/Co/Pt multilayers10.1038/nmat4934 ↗
8. Blowing magnetic skyrmion bubbles10.1126/science.aaa1442 ↗
9. Strong room-temperature ferromagnetism in VSe2 monolayers on van der Waals substrates10.1038/s41565-018-0063-9 ↗
10. Nonlinear magnetic vortex gyration10.1103/physrevb.85.144417 ↗
11. Vortex core-driven magnetization dynamics10.1126/science.1095068 ↗
12. Inductive detection of magnetic vortex gyration10.1103/physrevb.87.064420 ↗
13. Electrical switching of the vortex core in a magnetic disk10.1038/nmat1867 ↗
14. Dynamic origin of vortex core switching in soft magnetic nanodots10.1103/physrevlett.100.027203 ↗
15. Soliton-pair dynamics in patterned ferromagnetic ellipses10.1038/nphys173 ↗
16. Exchange explosions: Magnetization dynamics during vortex-antivortex annihilation10.1103/physrevlett.97.177202 ↗
17. Digital and analogue modulation and demodulation scheme using vortex-based spin torque nano-oscillators10.1038/s41598-020-68001-6 ↗
18. Non-volatile artificial synapse based on a vortex nano-oscillator10.1038/s41598-021-95569-4 ↗
19. Simulation of advanced MRAM devices for sub-ns switching
20. Nonlinear motion of magnetic vortex cores during fast magnetic pulses10.1103/physrevb.85.134414 ↗
21. Magnetic vortex core observation in circular dots of permalloy10.1126/science.289.5481.930 ↗
22. Optical manipulation of magnetic vortices visualized in situ by Lorentz electron microscopy10.1126/sciadv.aat3077 ↗
23. Properties of magnetic nanodots with perpendicular anisotropy10.1063/1.3631081 ↗
24. Relative vortex state control in a Co/Cu/Co pseudo-spin-valve ring10.7567/jjap.51.04dm04 ↗
25. Dynamics of magnetic vortex core switching in Fe nanodisks by applying in-plane magnetic field pulse10.1063/1.2811885 ↗
26. Size-specific magnetic configurations in electrodeposited epitaxial iron nanocuboids: From landau pattern to vortex and single domain states10.1021/acs.nanolett.2c00607 ↗
27. Free-standing 2D ironene with magnetic vortex structure at room temperature10.1016/j.matt.2021.11.029 ↗
28. In situ observation of magnetic vortex manipulation by external fields in amorphous CeFeB ribbon10.1016/j.actamat.2017.07.054 ↗
29. In situ observation of magnetic vortex in amorphous and nanocrystalline ribbons10.1063/9.0000251 ↗
30. On the magnetism of iron and steel10.26599/phys.2024.9320329 ↗
31. TEM and EELS measurements of interface roughness in epitaxial Fe/MgO/Fe magnetic tunnel junctions10.1103/physrevb.79.144413 ↗
32. Oxidation state and chemical shift investigation in transition metal oxides by EELS10.1016/j.ultramic.2012.03.002 ↗
33. Direct observation of internal spin structure of magnetic vortex cores10.1126/science.1075302 ↗
34. Magnetic vortex oscillator driven by d.c. spin-polarized current10.1038/nphys619 ↗
35. Magnetic imaging by ‘force microscopy’ with 1000 Å resolution10.1063/1.97800 ↗
36. 2. Lorentz microscopy: Theoretical basis and image simulations