scholarly journals Magnetic Properties and Control of Interatomic Distance at Interface of Artificial Superlattice.

1992 ◽  
Vol 31 (9) ◽  
pp. 826-828
Author(s):  
Masaaki Matsui ◽  
Seiji Mitani ◽  
Ayumu Kida
Keyword(s):  
Magnetic Properties ◽  
Interatomic Distance ◽  
And Control

scholarly journals Analysis of Modular Stator PMSM Manufactured Using Oriented Steel

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6583
Author(s):  
Anmol Aggarwal ◽  
Matthew Meier ◽  
Elias Strangas ◽  
John Agapiou
Keyword(s):  
Magnetic Properties ◽  
Interpolation Method ◽  
Core Loss ◽  
Rolling Direction ◽  
Element Analysis ◽  
Machine Performance ◽  
Core Losses ◽  
Lower Permeability ◽  
Improved Model ◽  
And Control

Oriented steel has higher permeability and lower losses in the direction of orientation (the rolling direction) than non-oriented steel. However, in the transverse direction, oriented steel typically has lower permeability and higher losses. The strategic use of oriented steel in a modular Permanent Magnet Synchronous Machine (PMSM) stator can improve machine performance, particularly when compared to a machine designed with non-oriented steel, by increasing both torque and efficiency. Typically, steel manufacturers provide magnetic properties only in the rolling and transverse directions. Furthermore, in modern Finite Element Analysis (FEA) software, the magnetic properties between the rolling and transverse directions are interpolated using an intrinsic mathematical model. However, this interpolation method has proven to be inaccurate; to resolve this issue, an improved model was proposed in the literature. This model requires the magnetic properties of the oriented steel in between the rolling and transverse directions. Therefore, a procedure for extracting the magnetic properties of oriented steel is required. The objective of this work is to propose a method of determining the magnetic properties of oriented steel beyond just the oriented and transverse directions. In this method, flux-injecting probes, also known as sensors, are used to inject and control the flux density in an oriented steel segmented stator in order to extract the properties of the oriented steel. These extracted properties are then used to model an oriented steel modular stator PMSM. The machine’s average torque and core losses are compared with conventional, non-modular, non-oriented steel stator PMSM, and modular, non-oriented steel stator PMSM. It is shown that both the average torque and the core loss of the oriented steel modular stator PMSM have better performance at the selected number of segments than either of the two non-oriented steel stators.

scholarly journals Preparation and Control of Magnetic Properties of Ultrafine Iron Particles by Chemical Vapor Deposition of Fe(CO)5.

1994 ◽  
Vol 20 (3) ◽  
pp. 367-372
Author(s):  
Yoshiaki Sawada ◽  
Yoshiteru Kageyama ◽  
Masashi Iwata ◽  
Shigehisa Harada ◽  
Akira Tasaki
Keyword(s):  
Magnetic Properties ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Iron Particles ◽  
And Control

scholarly journals Magnetic Nanoparticles: Co@SiO2, Co@Au and Co@Pt

2017 ◽  
Vol 36 (4) ◽  
pp. 01 ◽  
Author(s):  
Vagner Sargentelli ◽  
Antônio A. P. Ferreira
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Shell Structures ◽  
Human Organism ◽  
Core Shell ◽  
Present Moment ◽  
Metallic Oxides ◽  
The Core ◽  
Structure Changes ◽  
And Control

Nanotechnology is the understanding and control f matter at dimensions of roughly 1 – 100 nm. At the nanoscale, the properties like electrical conductivity and mechanical strength are not the same as the materials with particles in dimensions much more than 100 nm. The electronic structure changes dramatically too. Between nanomaterials, there is recently a great number of works that investing as the synthesis as the properties of the magnetic nanoparticles. The interest in these materials is due to its magnetic applications. Some of more representative magnetic materials are the metallic oxides, as some ferrites. However, the ferrites are often obtained as mixture of some oxides, which implies that the magnetic properties are not always well defined and reproducible. Thus, the researches has been turned to use of the magnetic metals, between which the cobalt. The cobalt is investigated because its high magnetic susceptility. However, this transition metal is easily oxidate in air and is toxic to human organism. For this reason, it has looked for to effect synthesis involving core – shell structures, which no to allow the oxidation of the cobalt and prevent against its toxicity. Between the shells that come being obtained it is of silica and of gold. In addition, in if treating to catalysis in a general way, the price of the cobalt and its magnetic properties are adjusted for the attainment core – shell catalysts, Cocore@Ptshell, (Co@Pt). So, the aim of this article is to present and to do an analysis of the more representative synthetic route used until the present moment to obtain the core – shell structures: Co@SiO2, Co@Au and Co@Pt.

scholarly journals Preparation and Control of Magnetic Properties of Ultrafine Iron Particles by Pyrolysis of Fe(CO)5.

1994 ◽  
Vol 43 (495) ◽  
pp. 1609-1614
Author(s):  
Yoshiaki SAWADA ◽  
Yoshiteru KAGEYAMA ◽  
Masashi IWATA ◽  
Shigehisa HARADA ◽  
Akira TASAKI
Keyword(s):  
Magnetic Properties ◽  
Iron Particles ◽  
And Control

Roles of charge state and interatomic distance in the magnetic properties of C-doped MgO

2015 ◽  
Vol 621 ◽  
pp. 52-57 ◽  
Author(s):  
Fang-Guang Kuang ◽  
Xiao-Yu Kuang ◽  
Shu-Ying Kang ◽  
Zhen-Hua Wang ◽  
Ai-Jie Mao
Keyword(s):  
Magnetic Properties ◽  
Charge State ◽  
Interatomic Distance

Improving the accuracy of time-harmonic FE simulations in induction heating applications

2017 ◽  
Vol 36 (2) ◽  
pp. 526-534 ◽  
Author(s):  
Kevin McMeekin ◽  
Frédéric Sirois ◽  
Maxime Tousignant ◽  
Philippe Bocher
Keyword(s):  
Magnetic Properties ◽  
Induction Heating ◽  
Design Methodology ◽  
Surface Heat ◽  
Equivalent Model ◽  
Content Type ◽  
Time Harmonic ◽  
Prediction And Control ◽  
Precise Prediction ◽  
And Control

Purpose Surface heat treatment by induction heating (10-100 kHz) requires precise prediction and control of the depth of the induced phase transformation. This paper aims at identifying common issues with the measurement and modeling of magnetic properties used in induction heating simulations, and it proposes ways to improve the situation. Design/methodology/approach In particular, it is demonstrated how intrinsic magnetic properties (i.e. the B-H curve) of a sample can change during the magnetic characterization process itself, due to involuntary annealing of the sample. Then, for a B-H curve that is supposed perfectly known, a comparison is performed between multiple models, each one representing the magnetic properties of steel in time-harmonic (TH) finite element method simulations. Finally, a new model called “power-equivalent model” is proposed. This model provides the best possible accuracy for a known nonlinear and hysteretic B-H curve used in TH simulations. Findings By carefully following the guidelines identified in this paper, reduction of errors in the range of 5-10 per cent can be achieved, both at the experimental and modeling levels. The new “power-equivalent model” proposed is also expected to be more generic than existing models. Originality/value This paper highlights common pitfalls in the measurement and modeling of magnetic properties, and suggests ways to improve the situation.

scholarly journals Nanoparticle shapes: Quantification by elongation, convexity and circularity measures

2019 ◽  
Vol 70 (7) ◽  
pp. 44-50
Author(s):  
Lazar Kopanja ◽  
Boris Lončar ◽  
Dragiša Žunić ◽  
Marin Tadić
Keyword(s):  
Magnetic Properties ◽  
Shape Analysis ◽  
Nanoparticle Synthesis ◽  
Synthesis Process ◽  
Shape Descriptors ◽  
Convex Shape ◽  
Size And Shape ◽  
And Control ◽  
Nanoparticle Shapes ◽  
Convexity Measure

Abstract The goal of the nanoparticle synthesis is, first of all, the production of nanoparticles that will be more similar in size and shape. This is very important for the possibility of studying and applying nanomaterials because of their characteristics that are very sensitive to size and shape such as, for example, magnetic properties. In this paper, we propose the shape analysis of the nanoparticles using three shape descriptors – elongation, convexity and circularity. Experimental results were obtained by using TEM images of hematite nanoparticles that were, first of all, subjected to segmentation in order to obtain isolated nanoparticles, and then the values of elongation, convexity and circularity were measured. Convexity Cx(S) is regarded as the ratio between shape’s area and area of the its convex hull. The convexity measure defines the degree to which a shape differs from a convex shape while the circularity measure defines the degree to which a shape differs from an ideal circle. The range of convexity and circularity values is (0, 1], while the range of elongation values is [1, ∞). The circle has lowest elongation (ε = 1), while it has biggest convexity and circularity values (Cx = 1; C = 1). The measures ε(S), Cx(S), C(S) proposed and used in the experiment have the few desirable properties and give intuitively expected results. None of the measures is good enough to describe all the shapes, and therefore it is suggested to use a variety of measures so that the shapes can be described better and then classify and control during the synthesis process.

A Monte Carlo Study of Molecular Spintronics Devices

2013 ◽  
Author(s):  
Pawan Tyagi ◽  
Christopher D’Angelo
Keyword(s):  
Monte Carlo ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Experimental Studies ◽  
Magnetic Molecules ◽  
Molecular Spintronics ◽  
Ferromagnetic Electrodes ◽  
Wide Range ◽  
And Control

Molecular spintronics devices (MSDs) are capable of harnessing the controllable transport and magnetic properties of molecular device elements and are highly promising candidates for revolutionizing computer logic and memory. These advanced MSD can enable the next generation of instrumentation and control devices for the wide range of mechanical engineering systems. A MSD is typically produced by placing magnetic molecule(s) between the two ferromagnetic electrodes. Recent experimental studies show that some magnetic molecules produced unprecedented strong exchange couplings between the two ferromagnetic electrodes, leading to intriguing magnetic and transport properties in a MSD. Future development of MSDs will critically depend on obtaining an in-depth understanding of the molecule induced exchange coupling, and its impact on MSD’s switchability, functional temperature range, stability etc. However, the large size of MSD systems and unsuitable device designs are the two biggest hurdles in theoretical and experimental studies of magnetic attributes produced by molecules in a MSD. This research theoretically studies the MSD by performing Monte Carlo simulations (MCS). The effect of magnetic molecule induced exchange coupling was studied at different temperature and for different device sizes — represented by a 2D Ising model. Our MCS shows that thermal energy of the MSD strongly influenced the molecular coupling effect. We studied the effect of a wide range of molecule-metal electrode couplings on the fundamental properties of MSDs. If molecules induced exchange coupling increased beyond a threshold limit a MSD acquired dramatically new attributes. Our MCS exhibited that the transition points in MSD’s magnetic properties was the interplay of temperature and molecular coupling strength. These simulations will allow the understanding of fundamental device mechanisms behind the functioning of novel MSDs. Our MSD model represents a myriad of magnetic molecules and ferromagnets combinations promising for realizing experimental MSDs. These MCS will also assist in designing new class of MSDs with desired attributes for advanced computers and control systems.

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