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Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques
Published on: July 2, 2018
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Magnetization reversal in circular vortex dots of small radius
M Goiriena-Goikoetxea1, K Y Guslienko, M Rouco
1Basque Center for Materials, Applications and Nanostructures (BCMaterials), Parque Tecnológico de Bizkaia, Building 500, Derio, Spain. maite.goiriena@bcmaterials.net.
Nanoscale
|August 1, 2017
Summary
This study reveals that small Permalloy nanodots exhibit classical vortex behavior, even with large vortex cores. This finding advances understanding of magnetic nanodots for spintronics and biomedical applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Permalloy (Ni80Fe20 alloy) nanodots are crucial for spintronic devices.
- Understanding magnetic vortex behavior in small nanodots is essential for device optimization.
Purpose of the Study:
- To investigate the magnetic behavior of small Permalloy nanodots (30-70 nm radii).
- To analyze the influence of large vortex core sizes on magnetic properties.
- To develop a model explaining magnetization reversal in these nanodots.
Main Methods:
- Experimental measurement of hysteresis loops.
- Magnetic force microscopy (MFM).
- Micromagnetic simulations.
- Development of an analytical model for magnetization reversal.
Main Results:
- Observed classical vortex behavior (zero remanence, high-field lobes) in small nanodots.
- Vortex core size was comparable to nanodot diameter.
- Magnetization states showed a mix of vortex, single domain, and skyrmion-like features.
- Analytical model showed good agreement with experimental data.
Conclusions:
- The study extends the understanding of magnetic nanodots beyond classical vortex concepts.
- Findings are applicable to improving spintronic devices like spin-torque nano-oscillators.
- Demonstrates feasibility of well-defined vortex configurations in sub-100 nm dots for biomedical applications.
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