scholarly journals Influence of Device Geometry on Transport Properties of Topological Insulator Microflakes

2021 ◽  
Vol 38 (11) ◽  
pp. 117302
Author(s):  
Fan Gao ◽  
Yongqing Li
Keyword(s):  
Magnetic Field ◽  
Topological Insulator ◽  
Current Density Distribution ◽  
Element Analysis ◽  
Transport Studies ◽  
Bulk Single Crystals ◽  
Field Geometry ◽  
High Carrier ◽  
The Magnetic Field ◽  
Geometry Correction

In the transport studies of topological insulators, microflakes exfoliated from bulk single crystals are often used because of the convenience in sample preparation and the accessibility to high carrier mobilities. Here, based on finite element analysis, we show that for the non-Hall-bar shaped topological insulator samples, the measured four-point resistances can be substantially modified by the sample geometry, bulk and surface resistivities, and magnetic field. Geometry correction factors must be introduced for accurately converting the four-point resistances to the longitudinal resistivity and Hall resistivity. The magnetic field dependence of inhomogeneous current density distribution can lead to pronounced positive magnetoresistance and nonlinear Hall effect that would not exist in the samples of ideal Hall bar geometry.

scholarly journals Finite Element Analysis of Magnetic Field Exciter for Direct Testing of Magnetocaloric Materials’ Properties

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2792
Author(s):  
Wieslaw Lyskawinski ◽  
Wojciech Szelag ◽  
Cezary Jedryczka ◽  
Tomasz Tolinski
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Circuit ◽  
Homogeneous Magnetic Field ◽  
Element Analysis ◽  
Mcm Testing ◽  
Testing Region ◽  
Magnetocaloric Materials ◽  
Field Excitation ◽  
The Magnetic Field

The paper presents research on magnetic field exciters dedicated to testing magnetocaloric materials (MCMs) as well as used in the design process of magnetic refrigeration systems. An important element of the proposed test stand is the system of magnetic field excitation. It should provide a homogeneous magnetic field with a controllable value of its intensity in the MCM testing region. Several concepts of a magnetic circuit when designing the field exciters have been proposed and evaluated. In the MCM testing region of the proposed exciters, the magnetic field is controlled by changing the structure of the magnetic circuit. A precise 3D field model of electromagnetic phenomena has been developed in the professional finite element method (FEM) package and used to design and analyze the exciters. The obtained results of the calculations of the magnetic field distribution in the working area were compared with the results of the measurements carried out on the exciter prototype. The conclusions resulting from the conducted research are presented and discussed.

Experimental Research on the Magnetic Field Sensitive Polymeric Actuator

2011 ◽  
Vol 287-290 ◽  
pp. 603-607
Author(s):  
Chun Lin Xia ◽  
Yang Fang Wu ◽  
Qian Qian Lu
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Conversion ◽  
Experimental Research ◽  
Experimental Results ◽  
Deformation Characteristics ◽  
Analysis Software ◽  
Element Analysis ◽  
The Magnetic Field

Using domestic MFSP membrane as a medium of energy conversion, a kind of MFSP actuator was designed. The dedicated test equipment was constructed for experimental research, and the experimental results were given. The strip and circular MSFP membrane were analyzed qualitatively to obtain the deformation characteristics of membrane by finite element analysis software.

Quantitative Research on Cracks in Pipe Based on Magnetic Field Response Method of Eddy Current Testing

2021 ◽  
Vol 36 (1) ◽  
pp. 99-107
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Li Tao
Keyword(s):  
Magnetic Field ◽  
Eddy Current ◽  
Quantitative Research ◽  
Three Dimensional ◽  
Impedance Analysis ◽  
Eddy Current Testing ◽  
Element Analysis ◽  
Defect Parameter ◽  
Current Testing ◽  
The Magnetic Field

The quantitative evaluation of defects in eddy current testing is of great significance. Impedance analysis, as a traditional method, is adopted to determine defects in the conductor, however, it is not able to depict the shape, size and location of defects quantitatively. In order to obtain more obvious characteristic quantities and improve the ability of eddy current testing to detect defects, the study of cracks in metal pipes is carried out by utilizing the analysis method of three-dimensional magnetic field in present paper. The magnetic field components in the space near the crack are calculated numerically by using finite element analysis. The simulation results confirm that the monitoring of the crack change can be achieved by measuring the magnetic field at the arrangement positions. Besides, the quantitative relationships between the shape, length of the crack and the magnetic field components around the metal pipe are obtained. The results show that the axial and radial magnetic induction intensities are affected more significantly by the cross-section area of the crack. Bz demonstrates obvious advantages in analyzing quantitatively crack circumference length. Therefore, the response signal in the three-dimensional direction of the magnetic field gets to intuitively reflect the change of the defect parameter, which proves the effectiveness and practicability of this method.

scholarly journals Development of a hybrid vibration converter for real vibration source / Entwicklung eines Hybrid-Vibrationswandlers für eine echte Schwingungsquelle

2019 ◽  
Vol 86 (s1) ◽  
pp. 57-61 ◽  
Author(s):  
Sonia Bradai ◽  
Slim Naifar ◽  
Olfa Kanoun
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Harvesting ◽  
Resonant Frequency ◽  
Ambient Vibration ◽  
Vibration Source ◽  
Frequency Bandwidth ◽  
Element Analysis ◽  
The Magnetic Field

AbstractHarvesting energy from ambient vibration sources is challenging due to its low characteristic amplitude and frequencies. In this purpose, this work presents a compact hybrid vibration converter based on electromagnetic and magnetoelectric principles working for a frequency bandwidth and under real vibration source properties. The combination of especially these two principles is mainly due to the fact that both converters can use the same changes of the magnetic field for energy harvesting. The converter was investigated using finite element analysis and validated experimentally. Results have shown that a frequency bandwidth up to 12 Hz with a characteristic resonant frequency at 24 Hz and a power density of 0.11mW/cm3 can be reached.

Finite Element Analysis of the Magnetic Field Simulation of High Temperature Superconducting Magnet

2014 ◽  
Vol 672-674 ◽  
pp. 562-566
Author(s):  
Ying Hong Luo ◽  
Jing Jing Wang
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Field Distribution ◽  
Magnetic Energy ◽  
Superconducting Magnet ◽  
Magnetic Field Distribution ◽  
Magnetic Storage ◽  
Element Analysis ◽  
The Magnetic Field

Superconducting Magnetic Energy Storage (SMES) system use conductive coils made of superconductor wire to store energy, its application entirely depends on the design and development of superconducting magnet, as the magnetic storage element, during the operation of the superconducting magnet generates relatively strong magnetic field. In this paper, a 1MJ class single solenoidal SMES with Bi2223/Ag conductor is presented. On the basis of electromagnetic theory, subsequently infers mathematical model of magnetic field distribution by ANSYS finite element analysis software, modeling a two-dimensional electromagnetic analysis of 44 double pancakes to get the magnetic field distribution patterns. The results of the analysis provide a reference for the structural design, optimization of a superconducting magnet and shielding of stray magnetic field.

The magnetic field geometry of HD 215441

1978 ◽  
Vol 222 ◽  
pp. 226 ◽  
Author(s):  
E. F. Borra ◽  
J. D. Landstreet
Keyword(s):  
Magnetic Field ◽  
Field Geometry ◽  
The Magnetic Field

The Magnetic Field Geometry in DR 21

2003 ◽  
Vol 125 (3) ◽  
pp. 1418-1425 ◽  
Author(s):  
Terry Jay Jones ◽  
Hassib Amini
Keyword(s):  
Magnetic Field ◽  
Field Geometry ◽  
The Magnetic Field

2-D Magnetic Field Analysis of Air Cylinder with MR Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 2706-2709
Author(s):  
Dan Jiang ◽  
Ping Yang ◽  
Kun Jiang
Keyword(s):  
Magnetic Field ◽  
Field Analysis ◽  
Magnetic Flux Density ◽  
Piston Motion ◽  
Element Analysis ◽  
Pneumatic Control ◽  
Magnetoresistive Sensor ◽  
Magnetic Field Analysis ◽  
Working Principle ◽  
The Magnetic Field

As a type of solid state switch, MR (magnetoresistive) sensor detects the air cylinder piston’s position in pneumatic control system. The construction and working principle of the air cylinder with MR sensor are introduced. Using 2-D magnetic field finite element analysis (FEA) method, the magnetic field distribution of air cylinder with piston motion is analyzed. Simulation results are given. The magnetic flux density characteristics are compared between piston wear or not.

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