scholarly journals Tемпературная зависимость магнитных свойств и магнитополевого поведения тонкопленочных трехслойных Co/Gd/Co систем

2021 ◽  
Vol 63 (10) ◽  
pp. 1542
Author(s):  
А.М. Харламова ◽  
А.В. Макаров ◽  
А.В. Свалов ◽  
Е.Е. Шалыгина
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Coercive Force ◽  
Magnetic Moment ◽  
Hysteresis Loops ◽  
Magnetic Characteristics ◽  
Temperature Changes ◽  
Ion Plasma ◽  
Temperature Dependences ◽  
Oriented Parallel

The results of studies of the temperature dependences of the magnetic properties and magnetic field behavior of thin-film three-layer Co/Gd/Co system, obtained by ion-plasma magnetron sputtering, are present. The thickness of the cobalt layers is 5.0 nm, and the thickness of the Gd layers, tGd, varies from 3.0 to 10.0 nm. The bulk magnetic characteristics of the samples are measured on a vibrating magnetometer at the external magnetic field oriented parallel to the plane of the samples. The influence of the temperature and Gd thickness on the shape of the hysteresis loops, the values of the magnetic moment m and coercive force are discovered. In particular, with the temperature changes from 100 to 300 K, the decrease of the coercive force is observed. At a temperature above 150 K, magnetic moment increases. With increasing thickness of gadolinium, the value of m decreases.

scholarly journals Structural and magnetic characteristics of the Co/Cu/Co thin-film systems

2018 ◽  
Vol 185 ◽  
pp. 03009
Author(s):  
Elena Shalygina ◽  
Anna Kharlamova ◽  
Andrey Makarov ◽  
Galina Kurlyandskaya ◽  
Andrey Svalov
Keyword(s):  
Thin Film ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Easy Magnetization Axis ◽  
Magnetic Characteristics ◽  
Easy Magnetization ◽  
Saturation Field ◽  
Glass Substrates ◽  
Magnetization Axis ◽  
Ferromagnetic Layers

The results on investigation of structural and magnetic characteristics of Co/Cu/Co thin-film systems obtained by magnetron sputtering on glass substrates are presented. The thickness of Co layers in all samples is equal to 5 nm and the Cu layer is varied from 0.5 to 4 nm. It is found that the saturation field, HS, oscillates in magnitude with increasing Cu layer thickness with the period of the order of 1 nm. The maximum values of HS are observed for tCu = 1.4, 2.2 and 3.2 nm. The hysteresis loops measured for these samples in a magnetic field applied along the easy magnetization axis have a two-step form, and for other tCu – rectangular one. The obtained results are explained by the presence of exchange coupling between the ferromagnetic layers through a Co spacer and its oscillating behavior with changing tCu.

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.

Effect of heat treatment on the magnetic behaviour of powder steel 50Ni2Mo under uni-axial tension

2011 ◽  
Vol 226 (6) ◽  
pp. 1462-1471 ◽  
Author(s):  
E S Gorkunov ◽  
Y V Subachev ◽  
S M Zadvorkin ◽  
A I Ulyanov ◽  
L S Goruleva
Keyword(s):  
Heat Treatment ◽  
Coercive Force ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Powder Steel ◽  
Magnetic Behaviour ◽  
Magnetic Characteristics ◽  
Internal Stresses ◽  
Treatment Conditions ◽  
Heat Treated

In this study, investigation results on the effect of heat treatment conditions on the mechanical properties, internal stresses, magnetic characteristics, and electrical resistivity of powder steel 50Ni2Mo are presented. Coercive force and maximum magnetization are shown to be applicable as magnetic test parameters to reveal underheating for quenching. Heating for quenching above the critical point [Formula: see text] up to 910°С has an insignificant effect on the mechanical characteristics of the steel tested. It has been demonstrated that the use of the coercive force measured on minor magnetic hysteresis loops is preferable when estimating the level of applied tensile stresses in heat-treated powder steel 50Ni2Mo.

scholarly journals Влияние толщины слоев гадолиния на магнитные свойства и процессы перемагничивания низкоразмерных Co/Gd/Co-систем

2019 ◽  
Vol 61 (3) ◽  
pp. 460
Author(s):  
А.М. Харламова ◽  
А.В. Свалов ◽  
В.Н. Лепаловский ◽  
Е.Е. Шалыгина
Keyword(s):  
Hysteresis Loops ◽  
Nanocrystalline Structure ◽  
Magnetic Characteristics ◽  
Saturation Field ◽  
X Ray ◽  
Plasma Sputtering ◽  
Ion Plasma ◽  
Oscillatory Character ◽  
The Mean ◽  
And Behavior

AbstractStructural and magnetic characteristics and behavior of thin-film Co/Gd/Co systems obtained by ion plasma sputtering in a magnetic field are reported. X-ray studies showed that cobalt layers in all investigated samples have a nanocrystalline structure. The mean roughness R a of the surface of the samples does not exceed 0.5 nm and is independent of the Gd layer thickness. The shape of hysteresis loops observed for the Co/Gd/Co system depends of the thickness of the Gd layer, t _Gd. The dependence of the saturation field H _S on t _Gd has an oscillatory character. This fact is explained by interaction of the Co layers through the intermediate Gd layer.

DIAGNOSTICS OF AMORPHOUS ALLOY MAGNETIC PROPERTIES AFTER THERMOMAGNETIC PROCESSING

2019 ◽  
pp. 30-37
Author(s):  
V. Yu. Vvedensky ◽  
G. A. Nuzhdin ◽  
S. V. Frolov ◽  
A. A. Gavrilov
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloy ◽  
Coercive Force ◽  
Magnetic Permeability ◽  
Hysteresis Loops ◽  
Soft Magnetic Materials ◽  
Magnetic Characteristics ◽  
Soft Magnetic ◽  
Low Field ◽  
Small Times

Hysteresis magnetic properties formation and plasticity of Fe&Co-based amorphous alloy tapes (brand 30KCP, the Fe–Co–Si–B system) for improvement increase in its properties and ensuring its competitive application on the control basis have been investigated. In researches magnetomeasuring installation have been used. It is intended for automatic magnetic characteristics measurement of soft magnetic materials ring samples by GOST 8.377 techniques. Defined degree of a flexural tension relaxation when annealing tapes. It was established that even at five-minute annealing at a temperature of 360 °C processes of a relaxation manage to take place almost completely. Further change in time of parameter of a relaxation is insignificant. The received dependences of magnetic characteristics on time of thermomagnetic processing at the enclosed field of 10 A/m and their comparison with usual annealing showed that coercive force changes on the same types of curves with insignificant deviations. After thermomagnetic processing in the enclosed field of 21 A/m coercive force in big fields increased approximately by 30 %, in small Hc failure observed around 5 … 15 min of processing as well as Br values increased. This observed result is very interesting in terms of magnetic reversal processes. The lack of stabilization mobile 180° domains borders, at simultaneous course stabilization 90° borders, is reflected in the form of recession of residual induction and growth of magnetic permeability. It is shown that thermomagnetic processing of amorphous alloy of brand 30KCP in not sating longitudinal field with small times of endurance 5…15 min at 360 °C leads to the drawn hysteresis loops, the lowered squareness of hysteresis loops and high values of low-field magnetic permeability 10.

scholarly journals SMALL-ANGLE SCATTERING OF NEUTRONS ON Sr2FeMoO6–δ SAMPLES WITH DIFFERENT-DEGREE SUPERSTRUCTURAL ORDERING OF Fe/Mo CATIONS

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 5-13
Author(s):  
L. I. Hurski ◽  
N. A. Kalanda ◽  
M. V. Yarmolich ◽  
I. A. Bobrikov ◽  
A. L. Zhaludkevich ◽  
...  
Keyword(s):  
Small Angle ◽  
Magnetic Moment ◽  
Solid Phase ◽  
Electronic Configuration ◽  
Magnetic Characteristics ◽  
Angle Scattering ◽  
Porod Law ◽  
Temperature Dependences ◽  
The Difference ◽  
Curie Temperatures

Single-phase Sr2FeMoO6-δ samples with different-degreesuperstructiral ordering Fe/Mo cations superstructural ordering (P, 76, 86 and 93 %) were obtained by the solid-phase technique. Based on the results of measuring the magnetic characteristics in the samples, we found that an increase in magnetization (26.41, 32.36 and 42.66 A·m2·kg–1), magnetic moment (1.33, 3.07 and 3.58 μB/f.u.) and Curie temperatures (422, 428 and 437 K) withparameter P (76, 86 and 93 %) can be explained by the presence of antistructural defects, as well as antiferromagnetic inclusions. This determines the redistribution of electron density, which is accompanied by the change in electronic configuration of a part of Fe/Mo cations. Based on the temperature dependences of the magnetic moment of the samples measured in ZFC and FC modes, and on small-angle polarized neutron scattering (SANS), we found that the samples are in a magnetically inhomogeneous state. An important result to mention is that we detected the difference between the slope of the SANS curves of samples with different oxygen content, which demonstrates a different microstructure of inhomogeneities. The main inhomogeneities are magnetic inclusions with the dimensions depending on the superstructural ordering of Fe/Mo cations. According to the Porod law, it was shown that the Sr2FeMoO6-δ samples with wave vector values 0.1 > q > 0.002 Å–1 contain polydisperse grains with a smooth surface. For q > 0.1 Å–1 a deviation from the Porod law is observed, confirming the presence of magnetic inhomogeneities with a diameter < 6 nm in the grains.

scholarly journals Влияние отжига в постоянном магнитном поле на магнитные свойства сплавов железо--галлий

2020 ◽  
Vol 62 (10) ◽  
pp. 1578
Author(s):  
В.А. Лукшина ◽  
Д.А. Шишкин ◽  
А.Р. Кузнецов ◽  
H.В. Ершов ◽  
Ю.Н. Горностырев
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Residual Induction ◽  
Dc Magnetic Field ◽  
Saturation Induction ◽  
Field Annealing ◽  
Gallium Content

The concentration dependence of the magnetic properties of iron alloys with 3 – 25 at.% gallium has been studied. It is shown that with increasing gallium content, saturation induction decreases monotonically, but coercive force shows a stepped increase with a jump from 85 to 135 A/m between 12 and 15 at.% Ga. The effect of annealing in a dc magnetic field (magnetic field annealing (MFA)) on the behavior of residual induction and coercive force in samples containing from 3 to 18 at.% of gallium was investigated. After the MFA, in the alloy a magnetic anisotropy is induced: magnetic hysteresis loops become narrower, the residual induction increases and the coercive force decreases. The MFA efficiency reaches a maximum when the gallium content is at 15 – 18 at.%. The features of the structural state in iron-gallium alloys and their role in the formation of the magnetic properties during annealing in the dc magnetic field are discussed.

scholarly journals Особенности структурных свойств и магнитополевого поведения тонкопленочных трехслойных Fe/полидифениленфталид/Fe-систем

2018 ◽  
Vol 60 (9) ◽  
pp. 1693
Author(s):  
Е.Е. Шалыгина ◽  
А.М. Харламова ◽  
А.В. Макаров ◽  
Т.П. Каминская ◽  
А.Н. Шалыгин
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Magnetic Properties ◽  
Hysteresis Loops ◽  
Step Size ◽  
Near Surface ◽  
Magnetic Layers ◽  
The Mean ◽  
Structural And Magnetic Properties ◽  
The Difference

AbstractThe structural and magnetic properties of thin-film Fe/poly(diphenylene phthalide) (PDP)/Fe systems are studied, along with the behavior of these systems in magnetic fields. The mean surface roughness of the studied samples is around 5–8 nm, and local near-surface magnetic properties show variation within 10%. The samples are characterized by two-step hysteresis loops, the step size depending on the thickness of the polymer layer and the difference in the thickness between the magnetic layers. The results are explained by the effects the exchange interaction between the magnetic layers, mediated by the PDP interlayer, has on the behavior of our samples in a magnetic field.

Physical methods of research and monitoring

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 35-44
Author(s):  
S. G. Sandomirski
Keyword(s):  
Heat Treatment ◽  
Coercive Force ◽  
Remanent Magnetization ◽  
Structural Changes ◽  
Mechanical Load ◽  
Magnetic Hysteresis ◽  
Steel Structures ◽  
Magnetic Characteristics ◽  
Magnetic Parameters ◽  
Saturation Intensity

The main magnetic parameters sensitive to the structure of steels are the parameters of their saturation loop of magnetic hysteresis: the coercive force Hcs and remanent magnetization Mrs. The saturation magnetization or saturation intensity Mr is most sensitive to the phase composition of steels. The variety of steel grades and modes of technological treatment (e.g., heat treatment, mechanical load) determined the use of magnetic structurescopy and magnetic characteristics — the coercive force Hc, remanent magnetization Mr , and specific hysteresis losses Wh on the subloops of the magnetic hysteresis of steels — as control parameters in diagnostics of the stressed and structural states of steel structures and pipelines. It has been shown that changes in Hc, Mr , and Wh are more sensitive to structural stresses and structures of steels than the parameters of the saturation hysteresis loop of magnetic hysteresis (Hcs, Mrs, and Mrs). The formulas for calculating Hc, Mr and Wh are presented to be used for estimation of changes in the parameters upon heat treatment of steels. Features of the structural sensitivity of the subloop characteristics and expediency of their use for magnetic structural and phase analyzes are determined. Thus, the range of changes in Ìr attributed to the structural changes in steels upon gradual Hm decrease is many times wider compared to the range of possible changes in Mrs under the same conditions. Conditions (relations between the magnetic parameters) and recommendations regarding the choice of the field strength Hm are given which provide the justified use of Hc, Mr and Wh parameters in magnetic structurescopy

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