scholarly journals Magnetically Induced Carrier Distribution in a Composite Rod of Piezoelectric Semiconductors and Piezomagnetics

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3115 ◽  
Author(s):  
Guolin Wang ◽  
Jinxi Liu ◽  
Wenjie Feng ◽  
Jiashi Yang
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Axial Magnetic Field ◽  
Semiconductor Layer ◽  
Carrier Distribution ◽  
Composite Rod ◽  
Piezoelectric Effects ◽  
Potential Applications ◽  
Piezoelectric Coupling ◽  
Piezoelectric Semiconductors

In this work, we study the behavior of a composite rod consisting of a piezoelectric semiconductor layer and two piezomagnetic layers under an applied axial magnetic field. Based on the phenomenological theories of piezoelectric semiconductors and piezomagnetics, a one-dimensional model is developed from which an analytical solution is obtained. The explicit expressions of the coupled fields and the numerical results show that an axially applied magnetic field produces extensional deformation through piezomagnetic coupling, the extension then produces polarization through piezoelectric coupling, and the polarization then causes the redistribution of mobile charges. Thus, the composite rod exhibits a coupling between the applied magnetic field and carrier distribution through combined piezomagnetic and piezoelectric effects. The results have potential applications in piezotronics when magnetic fields are relevant.

Study on non-uniform axial magnetic field induced deformation of soft cylindrical magneto-active actuator

Soft Matter ◽  
2021 ◽  
Author(s):  
Xiaocheng Hu ◽  
Yimou Fu ◽  
Tonghao Wu ◽  
Shaoxing Qu
Keyword(s):  
Magnetic Field ◽  
Magnetic Stimulation ◽  
Axial Magnetic Field ◽  
Soft Robots ◽  
Potential Applications

The magneto-active polymers (MAPs) can undergo rapid and noticeable deformation through the external wireless magnetic stimulation, offering a possibility to develop potential applications such as actuators, flexible micro-grippers, soft robots,...

Temperature Effects on Mobile Charges in Extension of Composite Fibers of Piezoelectric Dielectrics and Non-Piezoelectric Semiconductors

2019 ◽  
Vol 11 (09) ◽  
pp. 1950088 ◽  
Author(s):  
Ruoran Cheng ◽  
Chunli Zhang ◽  
Weiqiu Chen ◽  
Jiashi Yang
Keyword(s):  
Temperature Change ◽  
Composite Structures ◽  
Diffusion Theory ◽  
Composite Fiber ◽  
Macroscopic Theory ◽  
One Dimensional ◽  
Piezoelectric Effects ◽  
Potential Applications ◽  
Mobile Charges ◽  
Piezoelectric Semiconductors

We study the redistribution of mobile charge carriers in a composite fiber of piezoelectric dielectrics and non-piezoelectric semiconductors in extensional deformation under a uniform temperature change. The macroscopic theory of piezoelectricity and the drift-diffusion theory of semiconductor are used, coupled by doping and mobile charges. A one-dimensional model for extension is developed. Through a theoretical analysis, it is shown that under a temperature change the mobile charges in the semiconductor redistribute themselves under the polarization and electric field produced through thermoelastic, pyroelectric and piezoelectric effects. The results suggest the possibility of using composite structures for thermally manipulating mobile charges in semiconductors and have potential applications in piezotronics.

Behavior of Magnetorheological Fluids

MRS Bulletin ◽  
1998 ◽  
Vol 23 (8) ◽  
pp. 26-29 ◽  
Author(s):  
John M. Ginder
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Mr Fluid ◽  
Shock Absorbers ◽  
Aerospace Applications ◽  
Large Structures ◽  
Potential Applications ◽  
Restoring Forces ◽  
Newtonian Liquids ◽  
Er Fluids

In the absence of an applied magnetic field, magnetorheological (MR) fluids typically behave as nearly ideal Newtonian liquids. The application of a magnetic field induces magnetic dipole and multipole moments on each particle. The anisotropic magnetic forces between pairs of particles promote the head-to-tail alignment of the moments and draws the particles into proximity. These attractive interparticle forces lead to the formation of chains, columns, or more complicated networks of particles aligned with the direction of the magnetic field. When these structures are deformed mechanically, magnetic restoring forces tend to oppose the deformation. Substantial field-dependent enhancements of the rheological properties of these materials result, as demonstrated in Figure 1.The myriad potential applications of MR and electrorheological (ER) fluids provide considerable motivation for research on these materials. The availability of fluids with yield stresses or apparent viscosities that are controllable over many orders of magnitude by applied fields enables the construction of electromechanical devices that are engaged and controlled by electrical signals and that require few or no moving parts. Potential automotive applications include electrically engaged clutches for vehicle powertrains and engine accessories as well as semiactive shock absorbers that can adapt in real time to changing road conditions. Semiactive dampers for rotorcraft control surfaces are among the potential aerospace applications. The critical need to mitigate the structural vibrations of large structures has led to the construction of large, high-force MR-fluid-based dampers. A promising application in manufacturing processes is the computer-aided polishing of precision optics in which abrasive particles are suspended in an MR fluid so that the polishing rate is determined in part by the strength of an applied magnetic field.

"Magnetoactivated" Elastomer: An Alternative to Electroactive Polymer

2008 ◽  
Vol 144 ◽  
pp. 244-249 ◽  
Author(s):  
Yousef Razouk ◽  
Eric Duhayon ◽  
Bertrand Nogarede
Keyword(s):  
Magnetic Field ◽  
Magnetic Permeability ◽  
Applied Magnetic Field ◽  
Magnetic Particles ◽  
Young Modulus ◽  
Electroactive Polymer ◽  
Iron Particles ◽  
Silicon Matrix ◽  
Potential Applications ◽  
New Type

This paper deals with the development of a new type of composites called "magnetoactivated" polymers and the exploration of some of their potential applications. "Magnetoactivated" polymers consist of small embedding (micron-sized) magnetic particles in a high elastic silicon matrix to render it magnetically active and at the same time mechanically strong. The experimental characterizations obtained (magnetic permeability and Young modulus) were systematically compared with the values resulting from the modeling of this material.The elastic properties of our "magnetoactivated" silicon motive us to use them as pump membranes, the evolution of the displacement of the pump membrane with the applied magnetic field were verified in ANSYS and experimentally for various contents of iron particles in the silicon matrix.

scholarly journals Transverse electromagnetic Hermite–Gaussian mode-driven direct laser acceleration of electron under the influence of axial magnetic field

2018 ◽  
Vol 36 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Harjit Singh Ghotra ◽  
Dino Jaroszynski ◽  
Bernhard Ersfeld ◽  
Nareshpal Singh Saini ◽  
Samuel Yoffe ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Applied Magnetic Field ◽  
Axial Magnetic Field ◽  
Energy Gain ◽  
Electron Interaction ◽  
Direct Laser ◽  
Tem Mode ◽  
Laser Acceleration ◽  
Transverse Electromagnetic

AbstractHermite–Gaussian (HG) laser beam with transverse electromagnetic (TEM) mode indices (m, n) of distinct values (0, 1), (0, 2), (0, 3), and (0, 4) has been analyzed theoretically for direct laser acceleration (DLA) of electron under the influence of an externally applied axial magnetic field. The propagation characteristics of a TEM HG beam in vacuum control the dynamics of electron during laser–electron interaction. The applied magnetic field strengthens the $\vec v \times \vec B$ force component of the fields acting on electron for the occurrence of strong betatron resonance. An axially confined enhanced acceleration is observed due to axial magnetic field. The electron energy gain is sensitive not only to mode indices of TEM HG laser beam but also to applied magnetic field. Higher energy gain in GeV range is seen with higher mode indices in the presence of applied magnetic field. The obtained results with distinct TEM modes would be helpful in the development of better table top accelerators of diverse needs.

scholarly journals Subnanosecond breakdown of air-insulated coaxial line initiated by runaway electrons in the presence of a strong axial magnetic field

2021 ◽  
Vol 2064 (1) ◽  
pp. 012003
Author(s):  
G A Mesyats ◽  
E A Osipenko ◽  
K A Sharypov ◽  
V G Shpak ◽  
S A Shunailov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Voltage Pulse ◽  
Plasma Layer ◽  
Axial Magnetic Field ◽  
Coaxial Line ◽  
Runaway Electrons ◽  
Cathode Plasma ◽  
Fast Electrons

Abstract Flow of runaway electrons (RAEs) propagating in a radial, air-filled gap of coaxial line (CL) changes the dynamics of breakdown in the field of traveling voltage pulse. However, despite the effect of RAEs, breakdown does not occur if subnanosecond pulse is less in duration and amplitude than some values. In this work, we study the influence of an external axial magnetic field (B z) on the breakdown development. We demonstrate the transformation of the voltage pulse reflection from the ionized (breakdown) zone with changing B z. Due to gyration of fast electrons in an applied magnetic field, the gas region ionized by RAEs does not reach the anode. The ionized bridge between the cathode and anode is gradually replaced by a near-cathode plasma layer representing a discrete, reflecting/absorbing inhomogeneity in the CL.

Segregation During Magnetically-Stabilized Liquid-Encapsulated Growth of Compound Semiconductor Crystals

2000 ◽  
Author(s):  
Nancy Ma ◽  
David F. Bliss ◽  
George G. Bryant
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Applied Magnetic Field ◽  
Dopant Concentration ◽  
Axial Magnetic Field ◽  
Compound Semiconductor ◽  
Semiconductor Crystal ◽  
Semiconductor Crystals ◽  
Single Compound ◽  
Relative Motions

Abstract During the magnetically-stabilized liquid-encapsulated Czochralski (MLEC) process, a single compound semiconductor crystal is grown by the solidification of an initially molten semiconductor (melt) contained in a crucible. The melt is doped with an element in order to vary the electrical and/or optical properties of the crystal. During growth, the so-called melt-depletion flow caused by the opposing relative motions of the encapsulant-melt interface and the crystal-melt interface can be controlled with an externally applied magnetic field. The convective dopant transport during growth driven by this melt motion produces non-uniformities of the dopant concentration in both the melt and the crystal. This paper presents a model for the unsteady transport of a dopant during the MLEC process with an axial magnetic field. Dopant distributions in the crystal and in the melt at several different stages during growth are presented.

Finite deformations and incremental axisymmetric motions of a magnetoelastic tube

2017 ◽  
Vol 23 (6) ◽  
pp. 950-983 ◽  
Author(s):  
Prashant Saxena
Keyword(s):  
Magnetic Field ◽  
Internal Pressure ◽  
Applied Magnetic Field ◽  
Axial Magnetic Field ◽  
Cylindrical Tube ◽  
Axial Stretch ◽  
Mechanical Waves ◽  
Wave Guides ◽  
The Stability ◽  
Circular Cylindrical Tube

A thick-walled circular cylindrical tube made of an incompressible magnetoelastic material is subjected to a finite static deformation in the presence of an internal pressure, an axial stretch and an azimuthal or an axial magnetic field. The dependence of the static magnetoelastic deformation on the intensity of the applied magnetic field is analysed for two different magnetoelastic energy density functions. Then, superimposed on this static configuration, incremental axisymmetric motions of the tube and their dependence on the applied magnetic field and deformation parameters are studied. In particular, we show that magnetoelastic coupled waves exist only for particle motions in the azimuthal direction. For particle motion in radial and axial directions, only purely mechanical waves are able to propagate when a magnetic field is absent. The wave speeds as well as the stability of the tube can be controlled by changing the internal pressure, axial stretch and applied magnetic field that demonstrates the applicability of magneto-elastomers as wave guides and vibration absorbers.

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