Anti-function solution of uniaxial anisotropic Stoner-Wohlfarth model

2021 ◽  
Author(s):  
Kun Zheng ◽  
Yu Miao ◽  
Tong Li ◽  
Shuang-Long Yang ◽  
Li Xi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetization Reversal ◽  
Analytic Solution ◽  
Hysteresis Loops ◽  
Anisotropy Field ◽  
Dipole Interaction ◽  
Trigonometric Function ◽  
Switching Field ◽  
Function Solution

Abstract The anti-trigonometric function is used to strictly solve the uniaxial anisotropic Stoner-Wohlfarth (SW) model, which can obtain the relation of the angle α (θ) between the magnetization (the anisotropy field) and the applied magnetic field. Using this analytic solution, the hysteresis loops of uniaxial anisotropic SW particles magnetized in typical directions could be numerically calculated. Then, the hysteresis loops are obtained in randomly distributed SW particle ensembles while ignoring the dipole interaction among them with the analytic solution. Finally, the correctness of the analytic solution is verified by the exact solutions of remanence, switching field, and coercivity from SW model. The analytic solution provides an important reference for understanding the magnetizing and magnetization reversal processes of magnetic materials.

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 Heating ability of elongated magnetic nanoparticles

2021 ◽  
Vol 12 ◽  
pp. 1404-1412
Author(s):  
Elizaveta M Gubanova ◽  
Nikolai A Usov ◽  
Vladimir A Oleinikov
Keyword(s):  
Magnetic Field ◽  
Magnetite Nanoparticles ◽  
Volume Fraction ◽  
Low Frequency ◽  
Hysteresis Loops ◽  
Dipole Interaction ◽  
Alternating Magnetic Field ◽  
Particle Sizes ◽  
Order Of Magnitude ◽  
Elongated Nanoparticles

Low-frequency hysteresis loops and specific absorption rate (SAR) of various assemblies of elongated spheroidal magnetite nanoparticles have been calculated for a range of particle semiaxis ratios a/b = 1.0–3.0. The SAR of a dilute randomly oriented assembly of magnetite nanoparticles in an alternating magnetic field of moderate frequency, f = 300 kHz, and amplitude H0 = 100–200 Oe is shown to decrease significantly with an increase in the aspect ratio of nanoparticles. In addition, there is a narrowing and shift of the intervals of optimal particle diameters towards smaller particle sizes. However, the orientation of a dilute assembly of elongated nanoparticles in a magnetic field leads to an almost twofold increase in SAR at the same frequency and amplitude of the alternating magnetic field, the range of optimal particle diameters remaining unchanged. The effect of the magneto-dipole interaction on the SAR of a dilute assembly of oriented clusters of elongated magnetite nanoparticles has also been investigated depending on the volume fraction of nanoparticles in a cluster. It has been found that the SAR of the assembly of oriented clusters decreases by approximately an order of magnitude with an increase in the volume fraction of nanoparticles in a cluster in the range of 0.04–0.2.

Dipole-Dipole Interaction Between Particle Complexes in a Magnetophoretic Bioseparation Chip

2016 ◽  
Author(s):  
Manjurul Alam ◽  
Jeff Darabi
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Microfluidic Device ◽  
Applied Magnetic Field ◽  
Particle Motion ◽  
Computational Study ◽  
Particle Interaction ◽  
Dipole Interaction ◽  
Interaction Force ◽  
Particle Trajectories

Particle-particle interaction is an important phenomenon in the analysis of particle transport in a microfluidic device. This paper presents a computational study to predict the interaction force between particle complexes in a magnetophoretic bio-separation chip. Magnetic flux gradients are simulated in OpenFOAM CFD software and imported to Matlab to obtain the particle trajectories. The interaction force is approximated using a dipole based model and implemented to track the particle motion in a microfluidic device in the presence of an applied magnetic field. The analysis of particle trajectories is performed for cases where the applied magnetic field is parallel or perpendicular to the inter-particle distance of the particle complexes by solving a system of coupled ordinary differential equations.

Comparison of magnetoelastic properties between the 〈110〉 oriented TbxDy1-xFe1.95 polycrystalline alloys with different Tb/Dy composition ratio under magnetomechanical loading

2014 ◽  
Vol 28 (27) ◽  
pp. 1450187
Author(s):  
Pei Zhao ◽  
You-He Zhou ◽  
Zhong-Zheng Lin
Keyword(s):  
Magnetic Field ◽  
Coercive Force ◽  
Compressive Stress ◽  
Applied Magnetic Field ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Polycrystalline Alloys ◽  
Magnetoelastic Properties ◽  
Engineering Designs ◽  
Magnetostriction Hysteresis

This paper presents comparison of magnetoelastic properties between the 〈110〉 oriented Tb x Dy 1-x Fe 1.95 polycrystalline alloys for x = 0.27, 0.3, 0.45 under coupled loading of magnetic field and compressive stress. The simultaneously measure are investigated for the magnetization and magnetostriction under applied magnetic field from -200 to 200 kA/m and compressive stress from 0 to 50 MPa along the rod axis at room temperature. The results show that, according to the increase of Tb concentration and compressive stress, the hysteresis, coercive force and magnetostriction hysteresis loops of Tb x Dy 1-x Fe 1.95 alloys increase rapidly and the distortion of the hysteresis loops occurs at higher compressive stress, especially Tb 0.45 Dy 0.55 Fe 1.95 alloys, while the maximum relative permeability of Tb x Dy 1-x Fe 1.95 alloys monotonously decrease. Meanwhile, the higher the Tb concentration the stronger is magnetostrictive "jump" effect. For these experimental results, the effect of compressive stress and Tb / Dy ratio on magnetoelastic properties of Tb x Dy 1-x Fe 1.95 alloys are coupling and remarkable. A tradeoff and optimization are very important for many engineering designs and applications.

scholarly journals Динамика импульсного перемагничивания магнитоодноосных наночастиц

2019 ◽  
Vol 61 (10) ◽  
pp. 1783
Author(s):  
А.М. Шутый ◽  
Д.И. Семенцов
Keyword(s):  
Magnetic Field ◽  
Magnetic Moment ◽  
Magnetization Reversal ◽  
Magnetic Moments ◽  
Dipole Interaction ◽  
Pulse Action ◽  
Transverse Orientation ◽  
Final Orientation ◽  
Magnetizing Field ◽  
Peak Value

The magnetic moment response of a magneto-uniaxial nanoparticle and a flat lattice of similar nanoparticles are being studied under the action of a short Gaussian pulse of a magnetic field in the presence and in the absence of its modulation. The periodic dependence of the final orientation and duration of a response of the magnetic moments on the pulse duration and its peak value have been revealed and analyzed. The effect on processes magnetization reversal of a weak magnetizing field and the deviation of the pulse of field from the transverse orientation has been studied. Have been shown that the influence of the dipole-dipole interaction leads to modulation of the response to the pulse action.

Magnetization reversal process at low applied magnetic field in a Co-rich amorphous wire

2004 ◽  
Vol 343 (1-4) ◽  
pp. 369-373 ◽  
Author(s):  
V. Zhukova ◽  
A.P. Zhukov ◽  
N.A. Usov ◽  
J.M. Blanco ◽  
J. González
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetization Reversal ◽  
Amorphous Wire ◽  
Reversal Process ◽  
Magnetization Reversal Process

MAGNETIC MEASUREMENTS OF HIGH QUALITY SINGLE CRYSTAL YBa2Cu3O7-δ

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3697-3702
Author(s):  
A. TIRBIYINE ◽  
A. TAOUFIK ◽  
S. SENOUSSI
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Single Crystals ◽  
Applied Magnetic Field ◽  
Magnetic Measurements ◽  
Hysteresis Loops ◽  
High Quality ◽  
Flux Lines ◽  
Magnetization Hysteresis ◽  
Irreversible Magnetization

We have investigated the magnetic measurements on high quality single crystals of YBa 2 Cu 3 O 7-δ. Several magnetization hysteresis loops have been obtained for different temperature values, and as a function of the angle θ between the direction of the applied magnetic field and the c-axis of the sample. Measurements were performed at magnetic field up to 6 Tesla and various temperatures between 10 and 90 K. Magnetization hysteresis loops scale and shape are strongly dependent on the temperature values. Our results show that the magnetic properties are profoundly affected by flux lines pinning. The irreversible magnetization decreases as the applied magnetic field deviates from the c-axis (θ increases).

scholarly journals Optimal Control of Magnetization Reversal in a Monodomain Particle by Means of Applied Magnetic Field

2021 ◽  
Vol 126 (17) ◽  
Author(s):  
Grzegorz J. Kwiatkowski ◽  
Mohammad H. A. Badarneh ◽  
Dmitry V. Berkov ◽  
Pavel F. Bessarab
Keyword(s):  
Magnetic Field ◽  
Optimal Control ◽  
Applied Magnetic Field ◽  
Magnetization Reversal

scholarly journals Small-angle neutron scattering correlation functions of bulk magnetic materials

2015 ◽  
Vol 48 (5) ◽  
pp. 1437-1450 ◽  
Author(s):  
Denis Mettus ◽  
Andreas Michels
Keyword(s):  
Magnetic Field ◽  
Correlation Function ◽  
Magnetic Anisotropy ◽  
Neutron Scattering ◽  
Saturation Magnetization ◽  
Applied Magnetic Field ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Anisotropy Field ◽  
Two Dimensional

On the basis of the continuum theory of micromagnetics, the correlation function of the spin-misalignment small-angle neutron scattering cross section of bulk ferromagnets (e.g.elemental polycrystalline ferromagnets, soft and hard magnetic nanocomposites, nanoporous ferromagnets, or magnetic steels) is computed. For such materials, the spin disorder which is related to spatial variations in the saturation magnetization and magnetic anisotropy field results in strong spin-misalignment scattering dΣM/dΩ along the forward direction. When the applied magnetic field is perpendicular to the incoming neutron beam, the characteristics of dΣM/dΩ (e.g.the angular anisotropy on a two-dimensional detector or the asymptotic power-law exponent) are determined by the ratio of magnetic anisotropy field strengthHpto the jump ΔMin the saturation magnetization at internal interfaces. Here, the corresponding one- and two-dimensional real-space correlations are analyzed as a function of applied magnetic field, the ratioHp/ΔM, the single-particle form factor and the particle volume fraction. Finally, the theoretical results for the correlation function are compared with experimental data on nanocrystalline cobalt and nickel.

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