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

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.

Micromagnetic Simulation of Asymmetrical CoFe Nanorings

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.

Micromagnetic simulation of hysteresis loop of elliptic permalloy nanorings

2016 ◽  
Vol 30 (26) ◽  
pp. 1650192 ◽  
Author(s):  
Amaresh Chandra Mishra
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Magnetic Hysteresis ◽  
Major Axis ◽  
Micromagnetic Simulation ◽  
Hysteresis Curve ◽  
Semi Major Axis ◽  
Axis Length ◽  
20 Nm ◽  
The Magnetic Field

Magnetic hysteresis behavior of isotropic permalloy elliptic nanorings of outer semi-major axis length [Formula: see text] 100 nm and thickness [Formula: see text] 20 nm were studied with respect to the variation of two parameters: outer semiminor axis length [Formula: see text] and the difference between outer and inner dimensions [Formula: see text]. The outer semiminor axis length [Formula: see text] varied from 90 nm to 20 nm which covers from nearly circular nanoring to elliptic nanoring of high aspect ratio. The value of [Formula: see text] varied in steps of 10 nm. Micromagnetic simulation of in-plane hysteresis curve of these nanorings revealed that the remanent state of all of these elliptic rings are onion states if the magnetic field is applied along the longer side of the elliptic rings. If the magnetic field is applied along the shorter side, then the remanent states turn out to be vortex state. The hysteresis loss indicated by area of the hysteresis loop was found to be decreasing gradually with the increment of either [Formula: see text] or [Formula: see text]. On the other hand, the remanent magnetization increased with increment of [Formula: see text] but decreased with the increment of [Formula: see text]. The changes were attributed to three parameters mainly: inner curvature, exchange energy and demagnetization energy. The changes in loop area were discussed in light of variation of these three parameters.

Micromagnetic Simulation of CoFe Magnetic Nanorings: Switching Behavior in External Magnetic Field

2013 ◽  
Vol 710 ◽  
pp. 80-84 ◽  
Author(s):  
Zhen Gang Guo ◽  
Li Qing Pan ◽  
Hong Mei Qiu ◽  
M. Yasir Rafique ◽  
Shuai Zeng
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetization Reversal ◽  
Domain Walls ◽  
Vortex State ◽  
Switching Behavior ◽  
Switching Field ◽  
Reversal Process ◽  
Magnetic States ◽  
Magnetization Processes

The magnetization reversal processes of magnetic nanorings (Co50Fe50) with different geometric shapes are investigated. In addition to the expected onion and vortex magnetization states, other metastable states are observed in the magnetization processes. We anatomize the formation and transition of magnetic states, and the propagation and annihilation of domain walls in the reversal process through the dynamic picture. Phase diagrams for the magnetization switching behavior depending on the geometric parameters are presented. The simulation shows that the vortex state is stabilized in thick and narrow rings. The switching field from vortex to onion states turns out to increase with thickness and decrease with width and diameter.

Orientational Distributions of a Ferromagnetic Spherocylinder Particle in a Simple Shear Flow

2002 ◽  
Author(s):  
Masayuki Aoshima ◽  
Akira Satoh ◽  
Geoff N. Coverdale ◽  
Roy W. Chantrell
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Shear Flow ◽  
Flow Field ◽  
Simple Shear ◽  
Applied Magnetic Field ◽  
Spherical Particles ◽  
Simple Shear Flow ◽  
Microstructure Formation ◽  
Base Liquid

A ferrofluid is a suspension of ferromagnetic spherical particles in a base liquid (1), and is well known as a functional fluid which responds to an external magnetic field to give a large increase in the viscosity. Such a significant increase in the viscosity is due to the fact that chain-like clusters are formed owing to magnetostatic interactions between particles in an applied magnetic field. The microstructure formation offers a large resistance to a flow field that gives rise to a significant increase of the apparent viscosity (2).

The Kinematics of Cyclotron Emission for Quantized Electrons

1982 ◽  
Vol 4 (4) ◽  
pp. 359-362 ◽  
Author(s):  
D.B. Melrose ◽  
R.G. Hewitt ◽  
A.J. Parle
Keyword(s):  
Magnetic Field ◽  
Classical Theory ◽  
Major Axis ◽  
Lorentz Factor ◽  
Geometric Interpretation ◽  
Semi Major Axis ◽  
Electron Cyclotron Masers ◽  
Recent Developments ◽  
Cyclotron Emission ◽  
The Magnetic Field

Since the work of Wu and Lee (1979) there has been renewed interest in the classical theory of electron cyclotron masers (Lee and Wu 1980, Lee et al. 1980, Wu et al. 1981, 1982, Hewitt et al. 1981, 1982, Melrose et al. 1982, Omidi and Gurnett 1982, Melrose and Dulk 1982). A useful idea in these recent developments of the classical theory concerns a geometric interpretation of the classical gyroresonance conditionwhere Ωe, is the nonrelativistic gyrofrequency, s = 0, ± 1, ± 2,… is the harmonic number, is the Lorentz factor and ║ and ┴ denote components parallel and perpendicular to the magnetic field. In v┴ − v║ space (1) represents an ellipse with centre v║ = vc, v┴ = 0, eccentricity e0 and semi-major axis V parallel to the v┴ axis, with

FLUX FLOW EFFECTS IN VERY LONG JOSEPHSON JUNCTIONS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3032-3037 ◽  
Author(s):  
M. CIRILLO ◽  
V. MERLO ◽  
R. RUSSO ◽  
P. CIKMACS
Keyword(s):  
Magnetic Field ◽  
Numerical Modeling ◽  
External Magnetic Field ◽  
Applied Magnetic Field ◽  
Plasma Frequency ◽  
Flux Flow ◽  
One Dimensional ◽  
Flow Effects ◽  
Linear Slope ◽  
Josephson Plasma

We report on measurements on very long, L ≃ 30λj, NbAlOxNb underdamped in-line junctions, on which we observed displaced linear slope (DLS) generated by the application of an external magnetic field. We study the behaviour of the branches as a function of the applied magnetic field in terms of both current amplitude and voltage position. The DLS is seen to shift rigidly towards higher voltages when increasing the field, spanning a region roughly centred around the Josephson plasma frequency. We discuss the behaviour of linear branches in terms of one dimensional flux-flow along the extended side of the junction, comparing our data with the results of numerical modeling; from these calculations the non-resonant nature of DLS is very evident, in contrast to the resonant regime giving rise to Fiske steps (FS).

scholarly journals Controllable two- vs three-state magnetization switching in single-layer epitaxial Pd1-xFex films and epitaxial Pd0.92Fe0.08/Ag/Pd0.96Fe0.04 heterostructure

2021 ◽  
Author(s):  
Igor Yanilkin ◽  
Amir Gumarov ◽  
Gulnaz Gizzatullina ◽  
Roman Yusupov ◽  
Lenar Tagirov
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Applied Magnetic Field ◽  
Magnetization Reversal ◽  
Easy Axis ◽  
Magnetic State ◽  
Magnetic Moments ◽  
Single Layer ◽  
Wide Range ◽  
Ferromagnetic Layers

We have investigated the low-temperature magnetoresistive properties of a thin epitaxial Pd0.92Fe0.08 film at different directions of the current and the applied magnetic field. The obtained experimental results are well described within an assumption of a single-domain magnetic state of the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis. An epitaxial heterostructure of two magnetically separated ferromagnetic layers, Pd0.92Fe0.08/Ag/Pd0.96Fe0.04, was synthesized and studied with the dc magnetometry. Its magnetic configuration diagram has been constructed and the conditions have been determined for a controllable switching between stable parallel, orthogonal, and antiparallel arrangements of magnetic moments of the layers.

scholarly journals Vortex guide under a Lorentz force

2020 ◽  
pp. 101-106
Author(s):  
C. A. Aguirre ◽  
Q. Martins ◽  
Jose Barba
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
External Magnetic Field ◽  
Lorentz Force ◽  
Vortex State ◽  
Cooper Pairs ◽  
Magnetic Response ◽  
External Current ◽  
Critical Temperatures ◽  
Ginzburg Landau

In the present work we studied the effect of the nature of the contacts, by which a weak external current is applied, in an anisotropic superconducting rectangle, on the magnetization, magnetic susceptibility, density of the Cooper pairs and  (magnetic field for which the first vortices entry on the sample). The contacts are simulates by the  parameter, and the anisotropy is present in sections with different critical temperatures modeling for  function, both in the Ginzburg-Landau formalis. Also, the sample is embebbed in an external magnetic field . We established how the nature of the contacts and the presence of a weak Lorentz Force, influence the magnetic response and the vortex state of the sample.

The Temperature of Berezinsky – Kosterlitz – Thouless Transition in Two-Dimensional Superconductor in an External Field

2014 ◽  
Vol 9 (3) ◽  
pp. 75-80
Author(s):  
Aleksandr Krinitsyn ◽  
Iliya Tikhomirov ◽  
Klimentiy Yugay
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
External Magnetic Field ◽  
External Field ◽  
Critical Field ◽  
Applied Magnetic Field ◽  
Coherence Length ◽  
Upper Critical Field ◽  
Two Dimensional ◽  
Calculated Temperature

The Method of Monte-Carlo calculated temperature of Berezinsky – Kosterlitz – Thouless transition in twodimensional superconductor 2nd type in the presence of an external magnetic field. It is shown that near the upper critical field filling cells with a size of ξ × ξ relation, where ξ – coherence length at a given temperature, corresponds to half. It is also shown that ТBKT decreases with increasing interaction between the vortices and antivortices and increase of the external applied magnetic field

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