Development of Co-Rich Microwires with Graded Magnetic Anisotropy

In this paper, a gradual change in the hysteresis loop of Co-rich glass-coated microwire stress-annealed at variable temperature is observed. Such microwires annealed with a temperature gradient also present a variable squareness ratio and magnetic anisotropy field along the microwire’s length. The obtained graded anisotropy has been attributed to a gradual modification of the domain structure along the microwire originated by a counterbalance between shape, magnetoelastic, and induced magnetic anisotropies. Accordingly, we propose a rather simple route to design graded magnetic anisotropy in a magnetic microwire.

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Magnetic anisotropy field Hk and domain structure in L10 FexPt1−x films

Journal of Magnetism and Magnetic Materials ◽

10.1016/s0304-8853(01)00327-4 ◽

2001 ◽

Vol 235 (1-3) ◽

pp. 148-152 ◽

Cited By ~ 5

Author(s):

S. Ishio ◽

N. Mori ◽

T. Yoshino ◽

H. Saito ◽

T. Suzuki ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Domain Structure ◽

Anisotropy Field

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Multiscale Magnetic Anisotropy in Amorphous Ferromagnetic Ribbon: An Example of FeCuNdSiB Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.312.275 ◽

2020 ◽

Vol 312 ◽

pp. 275-280

Author(s):

Nikita Ilin ◽

Sergey Komogortsev ◽

Vitaliy Ivanov ◽

Galina S. Kraynova ◽

Alexander Davydenko ◽

...

Keyword(s):

Magnetic Properties ◽

Amorphous Alloy ◽

Magnetic Anisotropy ◽

Hysteresis Loop ◽

Domain Structure ◽

Easy Axis ◽

Anisotropy Constant ◽

Rolling Axis ◽

Magnetic Anisotropy Constant ◽

Amorphous Ribbons

An understanding of the magnetic properties in an amorphous alloy requires comprehensive studies of magnetic anisotropy at various scales. In this paper such a study is carried out using amorphous ribbons FeCuNbSiB. The magnetic anisotropy associated with the rolling axis of ribbons does not affect hysteresis loop measurements, but the disappearance of a fingerprint-like pattern in the domain structure occurs in different fields when they are applied along and transverse the rolling axis. A correlation between the local magnetic anisotropy constant and the nanoscale within which the local easy axis is ordered was found.

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Analytical Solutions and Derivation of Relative Permeabilities for Water-Heavy Oil Displacement and Gas-Heavy Oil Gravity Drainage Under Non-Isothermal Conditions

SPE Reservoir Evaluation & Engineering ◽

10.2118/179722-pa ◽

2016 ◽

Vol 19 (01) ◽

pp. 181-191 ◽

Cited By ~ 2

Author(s):

F. J. Argüelles-Vivas ◽

T.. Babadagli

Keyword(s):

Temperature Gradient ◽

Relative Permeability ◽

Heavy Oil ◽

Variable Temperature ◽

Spontaneous Imbibition ◽

Analytical Models ◽

Gravity Drainage ◽

Positive Temperature ◽

Relative Permeability Curves ◽

Isothermal Gas

Summary Analytical models were developed for non-isothermal gas/heavy-oil gravity drainage and water-heavy oil displacements in round capillary tubes including the effects of a temperature gradient throughout the system. By use of the model solution for a bundle of capillaries, relative permeability curves were generated at different temperature conditions. The results showed that water/gas-heavy oil interface location, oil-drainage velocity, and production rate depend on the change of oil properties with temperature. The displacement of heavy oil by water or gas was accelerated under a positive temperature gradient, including the spontaneous imbibition of water. Relative permeability curves were greatly affected by temperature gradient and showed significant changes compared with the curves at constant temperature. Clarifications were made as to the effect of variable temperature compared with the constant (but high) temperatures throughout the bundle of capillaries.

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Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.815.227 ◽

2015 ◽

Vol 815 ◽

pp. 227-232 ◽

Cited By ~ 2

Author(s):

Ying Yu ◽

Shu Hong Xie ◽

Qing Feng Zhan

Keyword(s):

Thin Films ◽

Magnetic Properties ◽

Magnetic Anisotropy ◽

Effective Strain ◽

Anisotropy Field ◽

Saturation Field ◽

Effective Anisotropy ◽

Magnetostriction Constant ◽

The Difference ◽

Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

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Interfacial control of domain structure and magnetic anisotropy in La0.67Sr0.33MnO3 manganite heterostructures

Physical Review B ◽

10.1103/physrevb.104.125423 ◽

2021 ◽

Vol 104 (12) ◽

Author(s):

Da Lan ◽

Pingfan Chen ◽

Chao Liu ◽

Xiaohan Wu ◽

Ping Yang ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Domain Structure

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Domain Structure of Perminvar Having a Rectangular Hysteresis Loop

Journal of Applied Physics ◽

10.1063/1.1702200 ◽

1952 ◽

Vol 23 (3) ◽

pp. 316-323 ◽

Cited By ~ 59

Author(s):

H. J. Williams ◽

Matilda Goertz

Keyword(s):

Hysteresis Loop ◽

Domain Structure ◽

Rectangular Hysteresis Loop

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Temperature Dependence of the Effective Magnetic Anisotropy Field and Ferromagnetic Resonance Linewidth in Polycrystalline Complex Substituted Magnetically Uniaxial Hexagonal Ferrites in the Frequency Range of 25–67 GHz

Technical Physics ◽

10.1134/s1063784220050230 ◽

2020 ◽

Vol 65 (5) ◽

pp. 749-753

Author(s):

S. V. Shcherbakov ◽

A. G. Nalogin ◽

V. G. Kostishin ◽

A. S. Semenov ◽

N. E. Adiatulina ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Temperature Dependence ◽

Ferromagnetic Resonance ◽

Anisotropy Field ◽

Hexagonal Ferrites ◽

Frequency Range ◽

Resonance Linewidth ◽

Effective Magnetic Anisotropy ◽

Ferromagnetic Resonance Linewidth

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Measurement of effective magnetic anisotropy field and ferromagnetic resonance bandwidth at ferromagnetic resonance frequency in magnetically uniaxial hexagonal ferrites

Modern Electronic Materials ◽

10.3897/j.moem.5.1.51295 ◽

2019 ◽

Vol 5 (1) ◽

pp. 33-39

Author(s):

Alexey S. Semenov ◽

Aleksey G. Nalogin ◽

Sergey V. Shcherbakov ◽

Alexander V. Myasnikov ◽

Igor M. Isaev ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Ferromagnetic Resonance ◽

Transmission Lines ◽

Anisotropy Field ◽

Nominal Composition ◽

Hexagonal Ferrites ◽

Magnetic Texture ◽

Measurement Results ◽

Effective Magnetic Anisotropy ◽

Ferromagnetic Resonance Frequency

In this work we have considered metrological problems and measurement of magnetic parameters and presented methods of measuring effective magnetic anisotropy field HAeff and ferromagnetic resonance bandwidth ∆H in magnetically uniaxial hexagonal ferrites in the electromagnetic microwave working frequency range. The methods allow measuring HAeff in the 10–23 and 28–40 kE ranges and ∆H in the 0.5–5.0 range. One method (suitable for wavelength measurements in free space in the 3-mm wavelength range) has been implemented for the 78.33–118.1 GHz range. The other method (based on the use of microstrip transmission lines) has been implemented for the 25–67 GHz range. The methods have been tested for polycrystalline specimens of hexagonal barium and strontium ferrites with nominal composition or complex substituted and having high magnetic texture. The measurement results have been compared with those obtained using conventional measurement methods and spherical specimens. Our methods prove to be highly accurate and reliable.

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MAGNETIC ELEMENTS OF NEURAL NETWORKS. PROPERTIES OF MAGNETIC INHOMOGENEITIES IN RESTRICTED GEOMETRIES

Izvestia Ufimskogo Nauchnogo Tsentra RAN ◽

10.31040/2222-8349-2021-0-1-81-86 ◽

2021 ◽

Vol 0 (1) ◽

pp. 81-86

Author(s):

A.R. MINIBAEVA ◽

◽

Z.V. GAREEVA ◽

Keyword(s):

Neural Network ◽

Neural Networks ◽

Magnetic Anisotropy ◽

Domain Structure ◽

Magnetic State ◽

Magnetic Nanostructures ◽

External Factors ◽

Magnetic Elements ◽

Magnetic States ◽

Moriya Interaction

This paper discusses the prospects for using magnetic nanostructures as elements of neural networks. At present neural network learning programs are actively used in analyzing and processing large data arrays; however, the development of computer technologies based on the neural network principle still remains open. Possibilities for using magnetic elements as physical carriers of information bits in these systems attract much attention from researchers and technologists due to the presence of several easily controlled parameters (order parameter) in the magnetic system, possibilities for the dimensionality reduction in magnetic elements by using magnetic nanostructures (domain boundaries, vortices, ckyrmions), superquick switching between magnetic states and some other factors. One of the key aspects of research in this regard is to determine basic controlled magnetic parameters in restricted geometries and to identify ways of controlling these parameters through internal and external factors. The paper presents a research on the magnetic ground state in restricted geometries. It deals with the magnetic state rebuilding in the system under changes in both external factors (applied magnetic field, sample dimensions) and internal ones (magnetic anisotropy constant, Dzyaloshinskii-Moriya interaction constant). Calculations were performed within the framework of micromagnetic modelling using the Object Oriented MicroMagnetic Framework ( OOMMF) sogtware. It is shown that the anisotropic exchange interaction (Dzyaloshinskii-Moriya interaction) has a significant effect on the magnetization distribution in restricted geometries. Namely, when changing the value of the Dzyaloshinskii-Moriya constant in the system with uniaxial magnetic anisotropy there is a series of phase transitions observed between magnetic states of different types: transitions from the homogenous magnetic state into the skyrmion-type vortex state (domain structure with the skyrmion-type unidomain state) with subsequent domain structure reversal when changing the value of the Dzyaloshinskii-Moriya constant. In the case of magnetic anisotropy of easy -axis type, chirality and properties of the structures in question do not depend on the constant symbol of the Dzyaloshinskii-Moriya interaction.

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