Related Experiment Video
Updated: Jan 5, 2026

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Narrow autoresonant magnetization structures in finite-length ferromagnetic nanoparticles
1Institute of Metal Physics, Ekaterinburg 620990, Russian Federation and Ural Federal University, Mira 19, Ekaterinburg 620002, Russian Federation.
Abstract:
The autoresonant approach to excitation and control of large-amplitude uniformly precessing magnetization structures in finite-length easy axis ferromagnetic nanoparticles is suggested and analyzed within the Landau-Lifshitz-Gilbert model. These structures are excited by using a spatially uniform, oscillating, chirped frequency magnetic field, while the localization is imposed via boundary conditions. The excitation requires the amplitude of the driving oscillations to exceed a threshold. The dissipation effect on the threshold is also discussed. The autoresonant driving effectively compensates the effect of dissipation but lowers the maximum amplitude of the excited structures. Fully nonlinear localized autoresonant solutions are illustrated in simulations and described via an analog of a quasiparticle in an effective potential. The precession frequency of these solutions is continuously locked to that of the drive, while the spatial magnetization profile approaches the soliton limit when the length of the nanoparticle and the amplitude of the excited solution increase.
Related Concept Videos
Ferromagnetism
Atomic Nuclei: Magnetic Resonance
Paramagnetism
Atomic Nuclei: Nuclear Relaxation Processes
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...

