scholarly journals FERROMAGNETIC NANOTUBES IN PORES OF TRACK MEMBRANES FOR THE FLEXIBLE ELECTRONIC ELEMENTS

2017 ◽  
Vol 8 (3) ◽  
pp. 214-221 ◽  
Author(s):  
E. Yu. Kaniukov ◽  
E. E. Shumskaya ◽  
M. D. Kutuzau ◽  
D. B. Borgekov ◽  
I. E. Kenzhina ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Soft Magnetic Materials ◽  
Magnetic Characteristics ◽  
Magnetic Memory ◽  
Magnetic Field Direction ◽  
Face Centered Cubic ◽  
Magnetic Parameters ◽  
Track Membranes ◽  
Ferromagnetic Nanotubes ◽  
Cobalt And Nickel

In the paper the template synthesis of ferromagnetic (Fe, Co, Ni) nanotubes in the pores of track membranes were studied. The aim of this work was determination of nanotubes basic structural and magnetic parameters and demonstration of the possibility of application in the flexible electronics elements.By electrochemical deposition, ferromagnetic nanotubes with a diameter of 110 nm and an aspect ratio of 100 were formed in the pores of polyethylene terephthalate track membranes. The morphology of the obtained nanostructures were studied by scanning electron microscopy, the elemental composition was determined by the energy-dispersion analysis. Using the X-ray structural analysis, the main parameters of the crystal structure were established: lattice type, lattice parameter and average crystallite size. The magnetic properties were studied by the method of vibrational magnetometry.It was shown that in the selected conditions of synthesis without reference to the type of ferromagnetic metals nanotubes had the same dimensions – length, diameter and wall thickness. The produced nanotubes consisted of iron, cobalt and nickel, respectively without oxides impurities. Nanotubes had a polycrystalline structure of walls with a body-centered cubic (iron), face-centered cubic (cobalt and nickel) crystal lattice. According to the main magnetic parameters, nanotubes belonged to a group of soft magnetic materials. Also, the presence of magnetic anisotropy, which is caused by the features of crystalline structure and shape of the nanostructures.Based on the analysis of structural and magnetic characteristics of ferromagnetic nanotubes which were synthesized in the pores of track membranes, were proposed the main principles of their using in the elements’ of flexible electronics constructing (magnetic field direction sensors and magnetic memory elements). 

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

Селективный магнитный контроль толщины и степени упрочнения поверхностных слоев на стальных объектах

2021 ◽  
pp. 39-45
Author(s):  
А.В. Бызов ◽  
Д.Г. Ксенофонтов ◽  
В.Н. Костин ◽  
О.Н. Василенко
Keyword(s):  
Magnetic Flux ◽  
Internal Field ◽  
Hardened Layer ◽  
Strength Properties ◽  
Hardened Steel ◽  
Magnetic Characteristics ◽  
Surface Layers ◽  
Magnetic Parameters ◽  
Maximum Value ◽  
Tangential Field

The dependences of measured locally magnetic characteristics of surface-hardened steel objects on the thickness and physical properties of their surface layers are studied. It is shown theoretically and experimentally that a change in the thickness of the hardened layer on the surface of steel objects affects on the magnitude of the tangential field component on the surface of the object in the interpolar space significantly , as well as the change in the strength properties of the layer affects the magnitude of the magnetic flux in the "transducer-object" circuit. It is proposed to use this difference in magnetic parameters for selective testing of the surface hardening quality. It is shown that the coercive force measured locally by the internal field and the maximum value of the magnetic flux, which can be measured using a single transducer in single measuring cycle, can be used as diagnostic parameters.

scholarly journals Study on Formation Process and Models of Linear Fe Cluster Structure on a Si(111)-7 × 7-CH3OH Surface

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1593
Author(s):  
Wenxin Li ◽  
Wanyu Ding ◽  
Dongying Ju ◽  
Ken-ichi Tanaka ◽  
Fumio Komori
Keyword(s):  
Formation Process ◽  
Surface Display ◽  
Cluster Structure ◽  
Scanning Tunneling ◽  
Magnetic Memory ◽  
Face Centered Cubic ◽  
Tunneling Microscopy ◽  
Height Measurement ◽  
Adsorption Sites ◽  
Spectrometer Data

STM results showed that Fe atoms were deposited on a Si(111)-7 × 7 reconstructed surface, which was saturated with CH3OH molecules. Fe atomic linear structure was composed of stable clusters and in-situ observed by the scanning tunneling microscopy (STM). The aim to improve its application of magnetic memory material, both formation process and models, has been explored in this paper. By combining surface images and mass spectrometer data, an intermediate layer model was established. In terms of thermal stability, the most favorable adsorption sites of CH3OH were further explored. After that, Fe atoms were deposited on the Si(111)-7 × 7-CH3OH surface, forming a linear cluster structure. On the one hand, a new Fe cluster model was put forward in this paper, which was established with height measurement and 3D surface display technology. This model is also affected by the evaporation temperature, which can be consistent with the atomic stacking pattern of face centered cubic structures. On the other hand, the slight height change suggested the stability of linear structures. Even in the condition of thin air introduction, Fe cluster showed a good performance, which suggested the possibility of magnetic memory application in the future. These investigations are believed to have, to a certain extent, increased the probability of forming Fe linear clusters on the surface of silicon substrate, especially according to the models and surface technology we adjusted.

Theoretical Modeling and Exact Solution for Extreme Bending Deformation of Hard-Magnetic Soft Beams

2020 ◽  
Vol 87 (4) ◽  
Author(s):  
Wei Chen ◽  
Lin Wang
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Exact Solutions ◽  
Flexible Electronics ◽  
Soft Materials ◽  
Theoretical Modeling ◽  
Magnetic Field Direction ◽  
Magnetic Actuation ◽  
Governing Equations ◽  
Analysis And Design

Abstract Hard-magnetic soft materials (HMSMs) manufactured by embedding hard-magnetic particles in soft materials belong to a new type of soft active materials. The abilities of fast and complicated transformations of hard-magnetic soft structures provide a promising technology for soft robotics, flexible electronics, and biomedical devices. It is significant to investigate the mechanical behaviors of hard-magnetic soft structures for their better applications. In this work, a hard-magnetic soft beam under an external magnetic field is theoretically modeled and the exact solutions for its mechanical responses are presented. First, the governing equations and boundary conditions are derived based on the principle of minimum potential energy. To solve the derived governing equations analytically, a new polynomial fitting model for hyperelastic materials is proposed for the hard-magnetic soft beam. Then, the exact solutions of a cantilevered hard-magnetic soft beam actuated by a uniform magnetic field in any direction are obtained. The newly derived exact solutions are further verified by comparing current results with those from recent simulations and experiments. For large bending angles up to 90 deg and extreme bending angle up to 180 deg, quite consistent agreement among exact solutions, numerical simulations, and experimental observations can be achieved. Finally, using our theoretical model, the deformation of the hard-magnetic soft beam actuated by magnetic fields in an arbitrary direction with non-zero magnetic declination is explored. When the magnetic actuation is increased from a small level gradually, the hard-magnetic soft beam deflects and it would undergo small, large, and extreme bending deformations in sequence. It is very interesting that, when the magnetic actuation is sufficiently large, the hard-magnetic soft beam is stretched and its centerline tends to align with the external magnetic field direction, implying that the hard-magnetic soft beam undergoes a uniaxial tension. The theoretical modeling and exact solutions for hard-magnetic soft beams are expected to be useful in the analysis and design of soft materials and structures.

scholarly journals Gel Synthesis of Hexaferrites Pb1−xLaxFe12−xZnxO19 and Properties of Multiferroic Composite Ceramics PZT–Pb1−xLaxFe12−xZnxO19

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1630
Author(s):  
Inna V. Lisnevskaya ◽  
Inga A. Aleksandrova
Keyword(s):  
Coupling Coefficient ◽  
Lead Titanate ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Magnetic Characteristics ◽  
Composite Ceramics ◽  
Magnetic Parameters ◽  
Lead Titanate Zirconate ◽  
Multiferroic Composite ◽  
Tan Δ

We investigated the opportunities for obtaining hexaferrites Pb1−xLaxFe12−xZnxO19 (x = 0–1) from citrate–glycerin gel and showed that synthesis occurs via the formation of the Fe3O4 phase; products with a small amount of hematite impurity Fe2O3 can be obtained after firing at 800 to 900 °C with 0 ≤ x ≤ 0.5. If x > 0.5, perovskite-like LaFeO3 is formed in samples, so that if x = 0.9–1, the synthesis products virtually do not contain phases with hexaferrite structures and represent a mixture of LaFeO3, Fe2O3, and Fe3O4. Within the range of 0 ≤ x ≤ 0.5, the electrical and magnetic characteristics of hexaferrites Pb1−xLaxFe12−xZnxO19 are slightly dependent on x and have the following average values: A relative permittivity ε/ε0 ~ 45, a dielectric loss tangent tan δ ~ 0.6, an electrical resistivity R ~ 109 Ohm cm, coercivity Hc ~ 3 kOe, saturation magnetization Ms ~ 50 emu/g, and remanent magnetization Mr ~ 25 emu/g. The magnetoelectric (ME) ceramics 50 wt.% PZTNB-1 + 50 wt.% Pb1−xLaxFe12−xZnxO19 (PZTNB-1 is an industrial piezoelectric material based on lead titanate zirconate (PZT) do not contain impurity phases and have the following characteristics: Piezoelectric coefficients d33 = 10–60 and −d31 = 2–30 pC/N, piezoelectric voltage coefficients g33 = 2–13 and −g31 = 1–5 mV m/N, an electromechanical coupling coefficient Kp = 0.03–0.13, magnetic parameters Hc = 3–1 kOe, Ms = 50–30, and Mr = 25–12 emu/g. The maximum ME coupling coefficient ΔE/ΔH ~ 1.75 mV/(cm Oe) was achieved with x = 0.5.

Magnetization Chirality of Ni-Fe and Ni-Fe/Mn-Ir Asymmetric Ring Dots for High-Density Memory Cells

2006 ◽  
Vol 512 ◽  
pp. 171-176 ◽  
Author(s):  
Isao Sasaki ◽  
Ryoichi Nakatani ◽  
Tetsuo Yoshida ◽  
Keiichi Otaki ◽  
Yasushi Endo ◽  
...  
Keyword(s):  
Ring Width ◽  
Vortex State ◽  
Magnetic Memory ◽  
Magnetic Field Direction ◽  
Memory Cells ◽  
Demagnetizing Field ◽  
Asymmetric Structures ◽  
Ring Structures ◽  
Wide Ring ◽  
20 Nm

The magnetic configurations of Ni-20at%Fe/Hf and Ta/Ni-20at%Fe/Mn-28at%Ir/ Ni-20at%Fe/Ta asymmetric ring dots have been studied. Recently, we proposed that asymmetric ring structures are suitable for magnetic memory cells and then demonstrated that asymmetric structures can control the chirality of the vortical magnetization with in-plane fields. The investigation of the Ni-20at%Fe(20 nm)/Hf(5 nm) asymmetric ring dots for free layers in magnetic memory cells demonstrated that switching fields cause a transition from the vortex state to the onion state that increases as the ring width decreases from 410 nm to 210 nm since a narrow ring has a higher demagnetizing field than that of a wide ring during the transition. The investigation of the Ta(3 nm)/Ni-20at%Fe(15 nm)/Mn-28at%Ir(10 nm)/Ni-20at%Fe(3 nm)/Ta(5 nm) asymmetric ring dots for the pinned layers in magnetic memory cells demonstrated that the chirality of the vortical magnetization is pinned regardless of the magnetic field direction.

scholarly journals Measuring And Computing System for Studying the Magnetic Characteristics of Soft Magnetic Materials

2021 ◽  
pp. 21-26
Author(s):  
A.V. Egorov ◽  
V.V. Polyakov ◽  
A.A. Lependin ◽  
D.D. Ruder
Keyword(s):  
Magnetic Properties ◽  
Eddy Current ◽  
Magnetic Permeability ◽  
Computing System ◽  
Ferromagnetic Materials ◽  
Soft Magnetic Materials ◽  
Magnetic Characteristics ◽  
Soft Magnetic ◽  
Non Destructive

Non-destructive eddy current diagnostics of the structure, composition, physical and mechanical properties of ferromagnetic materials, as well as eddy current monitoring of the operational parameters of products manufactured from them, requires knowledge of the magnetic characteristics of these materials. In eddy current measurements, the results obtained are influenced by a significant number of factors — magnetic and electrical properties of materials, geometric characteristics of products, measurement conditions, design features of an eddy current sensor, etc. Also, the magnetic properties themselves have high structural sensitivity. Thus, identification of the diagnosed parameters puts great importance on the tasks to separate the influencing factors and isolate the contribution of the magnetic properties. This paper describes the measuring and computing system that allows automatic determination of the magnetic permeability of soft magnetic ferromagnetic materials at various values of the strength of the external magnetizing field. The system has been tested using soft magnetic ferrites samples. An experimental dependence of the magnetic permeability on the magnitude of the magnetic field for the initial section of the main magnetization curve is presented. The obtained initial magnetic permeability is compared with the data of independent indirect measurements. The proposed system provides an increase in the reliability and accuracy of the results of the experimental determination of magnetic characteristics and can be used for non-destructive diagnostics of products made of soft magnetic ferromagnetic materials.

scholarly journals Compositional Design of Soft Magnetic High Entropy Alloys by Minimizing Magnetostriction Coefficient in (Fe0.3Co0.5Ni0.2)100−x(Al1/3Si2/3)x System

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 382 ◽  
Author(s):  
Yong Zhang ◽  
Min Zhang ◽  
Dongyue Li ◽  
Tingting Zuo ◽  
Kaixuan Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Base Alloy ◽  
Soft Magnetic Materials ◽  
Tensile Yield Strength ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
Soft Magnetic ◽  
High Entropy ◽  
Wide Range ◽  
Magnetostriction Coefficient

Developing cost-effective soft magnetic alloys with excellent mechanical properties is very important to energy-saving industries. This study investigated the magnetic and mechanical properties of a series of (Fe0.3Co0.5Ni0.2)100−x(Al1/3Si2/3)x high-entropy alloys (HEAs) (x = 0, 5, 10, 15, and 25) at room temperature. The Fe0.3Co0.5Ni0.2 base alloy composition was chosen since it has very the smallest saturation magnetostriction coefficient. It was found that the (Fe0.3Co0.5Ni0.2)95(Al1/3Si2/3)5 alloy maintains a simple face-centered cubic (FCC) solid solution structure in the states of as-cast, cold-rolled, and after annealing at 1000 °C. The alloy after annealing exhibits a tensile yield strength of 235 MPa, ultimate tensile strength of 572 MPa, an elongation of 38%, a saturation magnetization (Ms) of 1.49 T, and a coercivity of 96 A/m. The alloy not only demonstrates an optimal combination of soft magnetic and mechanical properties, it also shows advantages of easy fabrication and processing and high thermal stability over silicon steel and amorphous soft magnetic materials. Therefore, the alloy of (Fe0.3Co0.5Ni0.2)95(Al1/3Si2/3)5 holds good potential as next-generation soft magnets for wide-range industrial applications.

Study of the Reproducibility of Ni-Zn Nanoferrite Obtained by Combustion Reaction

2014 ◽  
Vol 775-776 ◽  
pp. 415-420 ◽  
Author(s):  
Débora Albuquerque Vieira ◽  
Verônica Cristina Souza Diniz ◽  
Daniel R. Cornejo ◽  
Ana Cristina Figueiredo de Melo Costa ◽  
Ruth Herta Goldsmith Aliaga Kiminami
Keyword(s):  
Electron Microscopy ◽  
Combustion Synthesis ◽  
Soft Magnetic Materials ◽  
Spherical Particles ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray ◽  
Crystallite Sizes ◽  
Scanning Electron

This work involved a study of the reproducibility of the process of combustion synthesis to produce Ni-Zn ferrites. The structural, morphological and magnetic characteristics of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetometry using an alternating gradient magnetometer (AGM). The XRD diffractograms of the samples indicated that they are monophasic, crystalline, with crystallite sizes ranging from 21 to 38 nm, and have a homogeneous morphology consisting of agglomerates of spherical particles. The samples behaved as soft magnetic materials, with magnetization levels ranging from 37 to 47 emug-1. The combustion synthesis was found to be efficient in producing Ni-Zn nanoferrites, yielding reproducible results.

scholarly journals A room-temperature electrical field–controlled magnetic memory cell

2007 ◽  
Vol 22 (8) ◽  
pp. 2111-2115 ◽  
Author(s):  
C. Cavaco ◽  
M. van Kampen ◽  
L. Lagae ◽  
G. Borghs
Keyword(s):  
Electric Fields ◽  
Lead Zirconate Titanate ◽  
Low Voltage ◽  
Uniaxial Anisotropy ◽  
Memory Cell ◽  
Lead Zirconate ◽  
Magnetic Characteristics ◽  
Magnetic Memory ◽  
Anisotropy Axis ◽  
Electrical Field

We present a method that allows changing the anisotropy and the magnetic characteristics of piezoelectric–ferromagnetic hybrid structures by electric fields, thereby suppressing the need for external or local magnetic fields. We have investigated the magnetic properties of single Co50Fe50 and CoFe80B20 magnetostrictive thin films as well as of high-quality bottom-pinned spin valves (SV) sputtered on piezoelectric substrates [lead zirconate titanate (PZT)] and patterned in an interdigitated transducer (IDT). Induction of a uniaxial anisotropy axis and the changes on coercivity and switching fields as a function of the applied bias voltage on the IDT are analyzed and interpreted. The down-scalability of this hybrid method supports the possibility of achieving low-power/low-voltage control of the switching fields and shows the feasibility of a hybrid ferroelectric magnetic memory cell.

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