scholarly journals Splitting of the Magnetic Loss Peak of Composites under External Magnetic Field

Physics ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 678-688
Author(s):  
Artem Shiryaev ◽  
Konstantin Rozanov ◽  
Andrey Naboko ◽  
Anastasia Artemova ◽  
Sergey Maklakov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Saturation Magnetization ◽  
Magnetic Loss ◽  
Coaxial Line ◽  
Al Alloy ◽  
Loss Peak ◽  
Permanent Magnetic Field ◽  
Alloy Particles ◽  
The Individual

Composite materials filled with ferromagnetic inclusions are useful in the development of various microwave devices. The performance of such devices is determined both by material properties (such as the saturation magnetization and the permeability) and by the demagnetization effects. The paper is devoted to the study of the demagnetization effect on the permeability measurements of composites under external magnetic bias. The microwave permeability of composites filled with flake sendust (Fe-Si-Al alloy) particles is measured as a function of frequency and the external magnetic field. The measurements are carried out by the Nicolson–Ross–Weir technique in a 7/3 coaxial line in the frequency range of 0.1 to 20 GHz by a vector network analyzer. It is found that the magnetic loss peak is split under external fields of more than 1.5 kOe. The main aim of this paper is to study the causes of this splitting and to interpret the observed magnetic loss peaks. To study this effect, the samples of various thicknesses and the samples with isotropic and anisotropic orientations of particles are measured. The particles in the anisotropic samples are oriented by a strong uniform magnetic field. At a small fraction of inclusions, the permanent magnetic field is demagnetized on the individual particles rather than the whole sample. The splitting of the magnetic loss peak of the isotropic sample is caused by different orientations of particles in the sample. At a high fraction of inclusions, the permanent magnetic field is demagnetized on the whole sample and the magnetic loss peak of the isotropic sample is not split. The saturation magnetization of the material is found by measurements under the external magnetic field of the anisotropic sample.

scholarly journals Unravelling the Anisotropic Behavior of Nickel—Wires Prepared through External Magnetic Field Assisted Hydrazine Reduction Method

2021 ◽  
Vol 11 (18) ◽  
pp. 8627
Author(s):  
Min-Soo Kim ◽  
Min-Ji Shin ◽  
Akshay Kumar ◽  
Kavita Kumari ◽  
Seok-Hwan Huh ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Anisotropy ◽  
Saturation Magnetization ◽  
Synthesis Method ◽  
Ferromagnetic Behavior ◽  
Geometrical Shape ◽  
Face Centered Cubic ◽  
Minimum Diameter ◽  
Hydrazine Reduction

Ni wires, prepared through a hydrazine reduction, were exposed to external magnetic fields of different geometrical shape and configuration during the synthesis denoted as Ni-Non-Magnetic, Ni-Double, Ni-Single, Ni-Ring. Their effect on the wire morphology, magnetization and magnetic anisotropy was then investigated via various characterization techniques viz. X-ray diffraction (XRD), high-resolution field emission scanning electron microscopy (HR-FESEM), and vibrating sample magnetometer (VSM). The polycrystalline single phase of the Ni-wires with face centered cubic symmetry was confirmed through the analysis of XRD patterns. Analysis of HR-FESEM images revealed that the Ni-particles were aligned in form of wire-like morphology. The Ni-single sample formed the wires with minimum diameter compared to the parent sample. The magnetization measurements performed at 300 K and 50 K demonstrated the ferromagnetic behavior of all the samples. The room temperature saturation magnetization (MS) and anisotropy constant (K) of the Ni-wires were reduced upon providing the external field during synthesis. However, the low temperature (50 K) magnetization behavior was rather opposing, indicating enhanced values of MS and K. Among all, Ni-ring sample showed maximum anisotropy with a value of 3.84 × 104 erg/cm3 at 50 K. The ambiguous nature of the anisotropic constant and saturation magnetization ascribed partly to the variation in diameters of Ni-wires and to the intermittent spin-spin exchange interactions of unaligned/partially aligned particles during the synthesis. Briefly, in the present study, it was established that the morphology and magnetic anisotropy of the Ni-wires could be tailored through the external magnetic field assisted synthesis method.

On Electrical Conductivity Measurements of Molten Metals by Inductive Technique

2004 ◽  
Vol 126 (3) ◽  
pp. 468-470 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Mihai Dupac ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Electrical Conductivity ◽  
Fluid Flow ◽  
External Magnetic Field ◽  
Electric Conductivity ◽  
Molten Metals ◽  
Conductivity Measurements ◽  
Permanent Magnetic Field ◽  
Rotating Liquid

In this paper, we propose a new relationship between the opposing mechanical torque and the electric conductivity of a rotating liquid specimen in a permanent external magnetic field of constant induction, which includes the effect of fluid flow. The proposed relationship was applied to describe the experimental data for a conductive specimens rotating in a permanent magnetic field.

The thermal capillary migration properties and controlling technique of ferrofluids

2017 ◽  
Vol 231 (11) ◽  
pp. 1441-1449 ◽  
Author(s):  
Qingwen Dai ◽  
Wei Huang ◽  
Jingqiu Wang ◽  
Xiaolei Wang
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Saturation Magnetization ◽  
Experimental Results ◽  
Migration Behavior ◽  
Thermal Gradients ◽  
Cold Regions ◽  
External Forces

The thermal capillary migration describes a phenomenon where the thermal gradients on the surface drive a liquid to flow from warm to cold regions in the absence of external forces. In industry, it is of great importance to prevent the migration since it would lead to lubricant starvation on the moving components. In this paper, ferrofluids are employed to control the migration. The influence of external magnetic field on the migration of ferrofluids is studied. The effects of volume and saturation magnetization of ferrofluids are also investigated. Experimental results demonstrate that the external magnetic field intensities have a significant obstruction effect on the migration behavior. An effective method using electromagnet to control the migration and re-concentrate the migrated lubricant is proposed.

Fluid Flow Effect in Electrical Conductivity Measurements of Molten Metals by Inductive Technique

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Mihai Dupac ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Electrical Conductivity ◽  
Fluid Flow ◽  
External Magnetic Field ◽  
Electric Conductivity ◽  
Molten Metals ◽  
Conductivity Measurements ◽  
Permanent Magnetic Field ◽  
Rotating Liquid

In this paper we propose a new relationship between the opposing mechanical torque and the electric conductivity of a rotating liquid specimen in a permanent external magnetic field of constant induction, which includes the effect of fluid flow. The proposed relationship was applied to describe the experimental data for a conductive specimen rotating in a permanent magnetic field.

FeNbVB ALLOY PARTICLES SUSPENDED IN LIQUID GALLIUM: INVESTIGATING THE MAGNETIC PROPERTIES OF THE MR SUSPENSION

2011 ◽  
Vol 25 (07) ◽  
pp. 947-955 ◽  
Author(s):  
GJERGJ DODBIBA ◽  
KENJI ONO ◽  
HYUN SEO PARK ◽  
SEIJI MATSUO ◽  
TOYOHISA FUJITA
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Iron Alloy ◽  
Testing Temperature ◽  
Liquid Gallium ◽  
Temperature Sensitive ◽  
Prepared Powder ◽  
Alloy Particles ◽  
The Magnetic Field

A MR suspension was prepared by dispersing silica-coated iron alloy particles into a liquid gallium. In other words, the iron alloy particles of 30 to 50 nm in diameter were first prepared and then coated with silica. Next, the particles were then suspended in a liquid Ga (assay: 99.9999%). In addition, the magnetic properties of the synthesized particles and suspension under the influence of the magnetic field were investigated. One of the main findings of this study is that the prepared powder showed a temperature sensitive of magnetization within the testing temperature range of 293–353 K. The saturation magnetization of silica-coated FeNbVB particles was about 0.55 T, whereas the saturation magnetization (297 K) of the synthesized MR suspension was 0.019 T.

The effect of an external magnetic field on the dealloying process of the Ni–Al alloy in alkaline solution

2017 ◽  
Vol 19 (28) ◽  
pp. 18167-18171 ◽  
Author(s):  
Haixia Zhang ◽  
Zhifeng Wang ◽  
Mingzhu Yang ◽  
Qibo Deng
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Alkaline Solution ◽  
Al Alloy

The dealloying process of the Ni–Al alloy is influenced by an external magnetic field and a finer morphology of nanoporous Ni is achieved.

scholarly journals RESEARCH ON WORK OF A STEPPER MOTOR OF ELECTRICITY METERS UNDER THE INFLUENCE OF AN EXTERNAL PERMANENT MAGNETIC FIELD CREATED WITH THE PURPOSE OF UNCOUNTED CONSUMPTION OF ELECTRIC ENERGY

2020 ◽  
Vol 22 (2) ◽  
Author(s):  
I. Bohdaniuk ◽  
S. Rohalin ◽  
V. Suprun
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Electric Power ◽  
Electrical Engineering ◽  
Electric Energy ◽  
Electrical Energy ◽  
Stepper Motor ◽  
Permanent Magnetic Field ◽  
Engineering Research ◽  
Forensic Examination

Research on facts and circumstances of electrical energy uncounted consumption in the practice of conducting electrical engineering forensic examination is one of the most common. Study of the influence of a permanent magnetic field on operation of the electromechanical electricity meters is one of the areas of electrical engineering research, where scientific and practical analysis is absent in electrical engineering forensic examination. The tasks solved by electrical engineering forensic examination of electricity meters subjected to interference in their work due to the influence of an external permanent magnetic field are still being solved indirectly, mainly by examining the state of indicators of the effect of a magnetic field. The Article purpose is to determine the mechanism of interference in the operation of a stepper motor of electromechanical electricity meters of energy accounting meters under the influence of an external magnetic field artificially developed to disregard the consumption of electric power. The article examines the structure of a stepper motor of electronic-mechanical devices metering electric power. A research model of a stepper motor is built. The analysis of distribution of force magnetic lines in the magnetic system and in the magnetic shield of a stepper motor as a result of influence of an external magnetic field artificially created for the purpose of uncounted consumption of electric power in the absence of such an effect on the basis of modeling with the use of software and a mathematical apparatus: the finite element method. The mechanism of interference in the regular operation of a stepper motor of electricity meter is determined when approaching the metering device of an external permanent magnet with a high value of maximum specific energy in order to consume electric power negligently.

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