Dynamic micromagnetic simulation of the magnetic spectrum of permalloy nanodot array with vortex state

Using micromagnetic simulation, the magnetization reversal of soft permalloy rings of torus shape with major radius R varying within 20–100 nm has been investigated. The minor radius r of the torus rings was increased from 5 nm up to a maximum value r[Formula: see text] such that R- r[Formula: see text] = 10 nm. Micromagnetic simulation of in-plane hysteresis curve of these nanorings revealed that in the case of very thin rings (r [Formula: see text] 10 nm), the remanent state is found to be an onion state, whereas for all other rings, the remanent state is a vortex state. The area of the hysteresis loop was found to be decreasing gradually with the increment of r. The normalized area under the hysteresis loops (A[Formula: see text]) increases initially with increment of r. It attains a maximum for a certain value of r = r0 and again decreases thereafter. This value r0 increases as we decrease R and as a result, this peak feature is hardly visible in the case of smaller rings (rings having small R).

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Micromagnetic simulation of magnetization reversal behavior of Co/Pt multilayer nanodot array prepared by colloidal lithograpy

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2004.09.029 ◽

2005 ◽

Vol 286 ◽

pp. 23-26 ◽

Cited By ~ 5

Author(s):

Dong-Hyun Kim ◽

Jong-Ryul Jeong ◽

Yoon-Chul Cho ◽

Sung-Chul Shin

Keyword(s):

Magnetization Reversal ◽

Micromagnetic Simulation ◽

Nanodot Array

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Micromagnetic simulation of the magnetic spectrum of ferromagnetic nanowire

Journal of Applied Physics ◽

10.1063/1.2829817 ◽

2008 ◽

Vol 103 (1) ◽

pp. 013910 ◽

Cited By ~ 23

Author(s):

Ronglin Liu ◽

Jianbo Wang ◽

Qingfang Liu ◽

Haixin Wang ◽

Changjun Jiang

Keyword(s):

Micromagnetic Simulation ◽

Magnetic Spectrum ◽

Ferromagnetic Nanowire

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Magnetization reversal in crossed double elliptic permalloy nanodisks studied by micromagnetic simulation

International Journal of Modern Physics B ◽

10.1142/s0217979218501564 ◽

2018 ◽

Vol 32 (13) ◽

pp. 1850156

Author(s):

Amaresh Chandra Mishra ◽

R. Giri

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Applied Magnetic Field ◽

Magnetization Reversal ◽

Major Axis ◽

Vortex State ◽

Micromagnetic Simulation ◽

Minor Axis ◽

Semi Major Axis ◽

Saturation State

The remanent state of elliptical permalloy nanodisks depends on the orientation of the applied magnetic field with respect to the major and minor axes of the nanodisks [A. C. Mishra, Int. J. Mod. Phys. B 30, 1650192 (2016)]. The remanent state is usually an onion state if the external magnetic field is along the major axis, and is a vortex state if the external magnetic field is along the minor axis. In this work, we have analyzed the magnetization reversal of a crossed elliptic disk of permalloy using micromagnetic simulation. This is a new shape where two identical elliptic disks with semi-major axis of length a and semi-minor axis of length b intersect such that they are perpendicular to each other. If the value of b is very close to that of a, then the remanent state is a near saturation state. As the ratio a/b goes down, new complex remanent states are observed. The hysteresis loss is found to be decreased gradually with the increment of b for a given value of b.

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Micromagnetic Simulation of Asymmetrical CoFe Nanorings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.529 ◽

2012 ◽

Vol 538-541 ◽

pp. 529-533

Author(s):

Zhen Gang Guo ◽

Li Qing Pan ◽

Hong Mei Qiu ◽

Xue Dan Zhao ◽

Li Hong Yang

Keyword(s):

Magnetic Field ◽

Domain Wall ◽

Applied Magnetic Field ◽

Magnetization Reversal ◽

Vortex State ◽

Micromagnetic Simulation ◽

Micromagnetic Simulations ◽

Vortex States

Domain wall motions and magnetization reversal processes in the nanoscale asymmetrical Co50Fe50rings have been studied using micromagnetic simulations. The results reveal that the switching fields and the plateau width of vortex state can be tuned through changing the asymmetrical parameter of magnetic nanorings. The chirality of vortex states can be easily controlled by the orientation of the applied magnetic field.

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Tuning the Magnetic Vortex State in Magnetite Nanodiscs for Remote Control of Biological Signalling

10.26434/chemrxiv.10299506.v1 ◽

2019 ◽

Author(s):

Danijela Gregurec ◽

Alexander W. Senko ◽

Andrey Chuvilin ◽

Pooja Reddy ◽

Ashwin Sankararaman ◽

...

Keyword(s):

Remote Control ◽

Ion Channels ◽

Ground State ◽

Magnetic Particles ◽

Colloidal Stability ◽

Vortex State ◽

Magnetic Vortex ◽

Electron Holography ◽

Dipole Interactions ◽

Magnetite Particles

In this work, we demonstrate the application of anisotropic magnetite nanodiscs (MNDs) as transducers of torque to mechanosensory cells under weak, slowly varying magnetic fields (MFs). These MNDs possess a ground state vortex configuration of magnetic spins which affords greater colloidal stability due to eliminated dipole-dipole interactions characteristic of isotropic magnetic particles of similar size. We first predict vortex magnetization using micromagnetic stimulations in sub-micron anisotropic magnetite particles and then use electron holography to experimentally investigate the magnetization of MNDs 98–226 nm in diameter. When MNDs are coupled to MFs, they transition between vortex and in-plane magnetization allowing for the exertion of the torque on the pN scale, which is sufficient to activate mechanosensitive ion channels in cell membranes.<br>

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