Combined Effect Of Electric Field Research Articles

The combined effects of electric field and embedded dielectric matrix on the electronic and optical properties in Ge/SiGe core/shell quantum dots and its SiGe/Ge inverted structure

In this study, the binding energy (BE) and photoionization cross-section (PICS) coefficients in a Ge/Si0.15Ge 0.85 core/shell quantum dots (CSQDs) and in its inverted structure Si0.15Ge0.85 / Ge (ICSQDs) are studied. The influence of the hydrogenic impurity and capped matrix are taken into account. The electronic states and their related eigenfunctions are computed by solving the three-dimensional Schrödinger equation under the framework of the effective mass approximation (E.M.A) using the variational dimensional. The influence of the core radius and electric field strength on the BE and PICS are investigated. The numerical results reveal that the optoelectronic properties are considerably affected by the electric field strength (EF), immersed oxide matrix (OM) and geometric parameter. The obtained results prove that the PICS magnitude increases as the core radius increases and its resonant peak moves towards the lower energies for Ge/Si0.15Ge0.85 CSQDs structure, and increases as the core radius decreases and its resonant peak experiences a blue shift with increasing core radius for Si0.15Ge 0.85/ Ge ICSQDs. Moreover, with the effects of the surrounding oxide matrix and electric field strength, the PICS magnitude is improved and their resonant peak suffers a redshift.

Influence of the optoelectronic properties of F-MoTe2 systems under the combined action of an external electric field and biaxial tensile-compressive deformation: a first-principles study

The effects of an applied electric field on the electronic structure, charge transfer, and optical characteristics of molybdenum telluride (MoTe2) systems doped with halogen F atoms during biaxial tensile-compressive deformation were explored using first-principles approaches. The results show that the MoTe2 system exhibits an upward shift of the Fermi energy level and a downward shift of the conduction band when crossing the Fermi energy level due to the doping of halogen F atoms. Subsequently, we applied an electric field of −0.4 eV∼−0.4 eV to the F-MoTe2 system. The change of the F-MoTe2 system under the electric field effect is very small. This result indicates that the F-MoTe2 system can be stabilized in this range. Subsequently, we chose to apply a biaxial tensile-compressive deformation of −14%−14% to the F-MoTe2 system under the action of an electric field of +0.4 eV. The F-MoTe2 system underwent a transition from a semiconductor to a metal, with an increase in the carrier concentration and a good shift in electrical conductivity. The compressive strain gives better results than the tensile strain. In terms of optical characteristics, the absorption and emission peaks of the F-MoTe2 system are blueshifted under the combined effect of electric field and stress.

Triggering of electro-elastic anti-superhydrophobicity during non-Newtonian droplet collision

The present article discusses the electrohydro-dynamics of impacting non-Newtonian dielectric droplets on superhydrophobic (SH) surfaces. The role of important parameters like electric Eotvos number ( Eo e ), Weber number ( We ), dielectric particle concentration ( TiO 2 ) and polymer concentration ( PEG-400 ) were elucidated in this experimental study. Due to the interplay of non-Newtonian effects and electric field, we had observed the suppression of drop rebound on SH surfaces at much lower Eo e compared to its Newtonian counterpart. It has been observed that with an increase in both polymer concentration or dielectric particle concentration, the suppression of drop rebounds was observed at lower Eo e. In order to encapsulate the combined effects of electric field and non-Newtonian dynamics on drop rebound suppression, we have introduced the ‘electro-elastic effect’. Contrary to the common observations of drop rebound on SH surfaces, this electro-elastic effect induces inhibition of drop rebound, thereby resulting in anti-superhydrophobicity. Subsequently, we also established a scaling relationship to show that the rebound suppression is observed as a manifestation of the onset of electro-elastic instability, when a proposed electric Weissenberg number ( Wi e ) exceeds unity. Finally, we demarcated the rebound and rebound suppression regimes of droplet dynamics through a detailed phase map.

Study the combined effect of electric field and variable viscosity on the stability of dielectric nanofluid (CuO + water) within a Hele–Shaw cell

In this research article, the combined effect of electric field and variable viscosity on the stability of dielectric nanofluid (CuO + water) within a Hele–Shaw cell is studied. The normal mode technique has been implemented for linear stability analysis and the truncated Fourier series method for nonlinear stability analysis. The effect of the Hele–Shaw number, thermorheological parameter, and alternating current electric Rayleigh number on the onset of convection and heat/mass transfer has been investigated analytically, graphically, and using tables. It is observed that the effect of the thermorheological parameter has a destabilizing effect, and the value of the parameter is always less than [Formula: see text] for this study. We also found that the Hele–Shaw number has stabilizing effect, and it is always greater or equal to [Formula: see text] for this study. The effect of alternating current electric Rayleigh number is destabilized. We observed that in the whole analysis, numerical results are better than analytical results.

Combined effect of electric field and nanofluid on bubble behaviors and heat transfer in flow boiling of minichannels

In this work, electric field and nanofluid are coupled to enhance flow boiling heat transfer in minichannel. Pin electrodes are adopted to create non-uniform electric field. The effects of nanoparticle mass concentration, surfactant type and mass concentration under electric field on nanofluid flow boiling heat transfer are studied. Image analysis technique is used to quantify boiling bubble behaviors. The results demonstrate that without electric field, bubbles for nanofluid flow boiling are smaller and more discrete than R141b. Under electric field, bubble size reduces and the number of bubbles increases, which reveals synergy effect of electric field and nanofluid on bubble behaviors is effective. Besides, electric forces mitigate bubble coalescence and delay transition from bubbly to slug flow. Maximum heat transfer coefficient of nanofluid is 80% higher than R141b. Under electric field, boiling heat transfer of nanofluid modified by anionic surfactant (SDBS) is better than cationic (CTAB) and nonionic (Span80) surfactant. • Electric field and nanofluid were devised to enhance flow boiling of minichannel. • Bubble behaviors and flow pattern transition in nanofluid flow boiling under electric field was discussed. • Synergy effects of electric field and nanofluids on enhancing flow boiling heat transfer was discussed. • Maximum heat transfer enhancement ratio of 1.8 for nanofluid and electric field is obtained.

The time delay between the equatorial ionization anomaly and the equatorial electrojet in the eastern Asian and American sectors

The daily evolution of the Equatorial Ionization Anomaly (EIA) and the Equatorial Electrojet (EEJ) exhibits phase difference, which reflects the response time of the F-region equatorial plasma fountain to the E-region electric field variation. Studies on this response time contribute to clarifying the relative importance of different influence factors on the low-latitude E- and F-region coupling process. However, the solar-cycle, seasonal and longitudinal dependence of this response time has not yet been comprehensively revealed. In this paper, the occurrence time of the daytime most developed northern EIA crest (TEIA), the occurrence time of the daytime strongest EEJ (TEEJ), and their time delay (δT = TEIA-TEEJ) during 2008 to 2018 are derived from total electron content and magnetometer data, and the seasonal and solar-cycle variations of these parameters are analyzed and compared between the eastern Asian and American sectors. Main results are as follows. (1) TEIA and δT share similar seasonal and solar-cycle variation patterns, which are different from TEEJ. (2) The prevailing seasonal variation pattern of TEIA is generally consistent in the two sectors, which is earlier (later) in the boreal winter (summer). This feature is not determined by the variations of TEEJ or EEJ strength. (3) The solar-cycle variation pattern of TEIA is different between the eastern Asian and American sectors, but the 11-yr averaged TEIA is nearly the same in the two sectors. The solar-cycle and longitudinal dependencies are probably due to the combined effect of electric field, meridional wind, and local geomagnetic field configuration.

Dynamics of double emulsion interfaces under the combined effects of electric field and shear flow

Dynamics of double emulsion interfaces under the combined effects of electric field and shear flow

Systematic competition between strain and electric field stimuli in tuning EELS of phosphorene

The strongly anisotropic properties of phosphorene makes it an attractive material for applications in deciding the specific direction for different purposes. Here we have particularly reported the competition between strain and electric field stimuli in evaluating the band gap and electron energy loss spectrum (EELS) of single-layer black phosphorus using the tight-binding method and the Kubo conductivity. We construct possible configurations for this competition and evaluate the interband optical excitations considering the corresponding band gap variations. The band gap increases with the individual electric field, while it increases (decreases) with tensile (compressive) uniaxial in-plane strain. Contrary to the in-plane strains, the uniaxial out-of-plane strain shows a critical strain at which the system suffers from a phase transition. Furthermore, the presence of these stimuli simultaneously results in an extraordinary band gap engineering. Based on the EELS response in the electromagnetic spectrum, the armchair (zigzag) direction is classified into the infrared and visible (ultraviolet) region. We report that the electric field gives rise to the blue shift in the interband optical transitions along the armchair direction, while the compressive/tensile (tensile/compressive) in-plane/out-of-plane strain provides a red (blue) shift. Moreover, we observe an inverse behavior of EELS response to the individual and combined effects of electric field and strains compared to the band gap behavior except at critical out-of-plane strain for which the physical theory of interband excitation is simply violated. Our results provide a new perspective on the applicability of phosphorene in stimulated optical applications.

Impact of AC/DC electric field in thermally generated dissolved gases in transformer oil

Here we report the combined effect of electric field with thermal stress on dissolved gas analysis (DGA). Dissolved gases detected from accelerated aging experiments show that AC electric field combined with thermal stress leads to higher gas generation than DC electric field with thermal stress or by thermal stress alone. Research reveals that the differences are caused by the divergent migration properties of the charged components under AC and DC electric fields. A mathematical explanation correlates the DGA results by proposing a carrier recombination coefficient parameter. The study suggests that dissolved gas content does not reflect the insulation performance of transformers by simply employing DGA without considering the operating condition of the transformer. It is essential that a comprehensive evaluation criterion should accompany DGA in order to accurately determine the insulation status.

Influence of cation types on the stability of bound chloride ions in cement mortar simultaneously under electric field and SO42− attack

Destabilization and release of bound chloride ions in reinforced concrete structures can cause accelerated corrosion of steel bars, posing an attendant risk to the durability of the whole structure and this problem is exacerbated by the combined effect of SO42− and electric field. In this paper, electrochemical chloride removal (ECR) method was used to remove chloride ions from mortar specimens and the influence of four cations (Mg2+, Ca2+, Na+ and K+) on the stability of bound chloride ions in cement mortars simultaneously under an electric field and SO42− attack was investigated. The results showed that bound chloride ions were prone to converting into free chloride ions under the combined effect of electric field and SO42− attack. Moreover, divalent cations (Mg2+ and Ca2+) exerted a more negative effect on the stability of bound chloride ions than monovalent cations (Na+ and K+). X-ray diffraction (XRD) analysis and thermal gravimetric and differential thermal gravimetric (TG-DTG) analysis demonstrated that the destabilization of bound chloride ions under an electric field was mainly attributed to the decomposition of the C-S-H gels and Friedel’s salts. Findings from this research shed new light on the fate of bound chloride ions in reinforced concrete structures under an electric field in chloride-sulfate coexistence environments.

Combined treatment of electrical and ethylene-vinyl acetate copolymer (EVA) to improve the cold flowability of waxy crude oils

Flow assurance issues related to wax precipitation, are one of the most challenging problems in the pipeline transportation of waxy crude oils. Flowability of waxy oils can be improved by suitable pour point depressants (PPDs). Besides chemical treatments, exposing waxy oils to high-voltage electric fields can also significantly improve their cold flowability. However, the combined effect of electric fields and PPD on the flowability of waxy oils is not yet clear. In this investigation, the effect of the combined electrical and EVA treatment on the flow properties of a waxy crude oil was studied.It is found that the combined treatment can lead to more significant reductions in the viscosity, the yield stress and the thixotropy of waxy oils compared to oils treated solely by electric field or EVA. However, the overall improvement in the flowability achieved by the joint treatment is lower than the sum of improvements achieved by the electric field and EVA. The combined treatment outperforms the individual treatments for hours under a low shear of 10 s−1. However, the performance cannot be preserved even for minutes under a high shear of 1200 s−1. Reheating has a negative impact on the electrical treatment, but an intricate impact on the EVA treatment and the combined treatment. The electrical- and chemical performance both undermine upon reheating, but chemical performance can be partially recovered when reheating temperature is above the wax disappearance temperature.Microscopic observation showed that the combined treatment leads to larger size and broader size distribution of wax particles.

Optical properties in GaAs/AlGaAs semiparabolic quantum wells by the finite difference method: Combined effects of electric field and magnetic field

In the present work, the optical properties of GaAs/AlGaAs semiparabolic quantum wells (QWs) are studied under the effect of applied electric field and magnetic field by using the compact-density-matrix method. The energy eigenvalues and their corresponding eigenfunctions of the system are calculated by using the differential method. Simultaneously, the nonlinear optical rectification (OR) and optical absorption coefficients (OACs) are investigated, which are modulated by the applied electric field and magnetic field. It is found that the position and the magnitude of the resonant peaks of the nonlinear OR and OACs can depend strongly on the applied electric field, magnetic field and confined potential frequencies. This gives a new way to control the device applications based on the intersubband transitions of electrons in this system.

Electric field tunable thermal stability of energy storage properties of PLZST antiferroelectric ceramics

AbstractThe electrical hysteresis behaviors and energy storage performance of Pb0.97La0.02(Zr0.58Sn0.335Ti0.085)O3 antiferroelectric (AFE) ceramics were studied under the combined effects of electric field and temperature. It was observed that the temperature dependence of recoverable energy density (Wre) of AFE ceramics depends critically on the applied electric field. While Wre at lower electric fields (<8 kV/mm) shows increasing tendency with increasing temperature from 20°C to 100°C, Wre at higher electric fields (>8 kV/mm) demonstrates decreasing dependence. There exists an appropriate electric field (8 kV/mm) under which the AFE ceramics exhibit nearly temperature‐independent Wre (the variation is less than 0.5% per 10°C). The underlying physical principles were also discussed in this study. These results indicate that the temperature dependence of Wre of AFE materials can be tuned through selecting appropriate electric fields and provide an avenue to obtain thermal stable energy storage capacitors, which should be of great interest to modern energy storage community.

Physics of the Switching Kinetics in Resistive Memories

Memristive cells based on different physical effects, that is, phase change, valence change, and electrochemical processes, are discussed with respect to their potential to overcome the voltage–time dilemma that is crucial for an application in storage devices. Strongly non‐linear switching kinetics are required, spanning more than 15 orders of magnitude in time. Temperature‐driven and field‐driven crystallization, threshold switching, ion migration, as well as redox reactions at interfaces are identified as relevant mechanisms. In phase change materials the combination of a reversible threshold switching and extremely large crystal growth velocities at high voltages enables ultra‐fast resistive switching whereas lower voltages will not be sufficient to overcome the energy barrier for crystallization. In electrochemical cells it depends on the voltage regime, which mechanism is the rate‐determining one for switching. While electro‐crystallization dominates at low voltages, electron transfer in the medium voltage range and a mixture of electron transfer and ion migration at high voltages. In valence change materials, ion migration is found to be accelerated by a combined effect of electric field and local temperature increase due to Joule heating. All discussed types of resistive switches can provide sufficient non‐linearity of switching kinetics for overcoming the voltage time dilemma.

Edge wave propagation in an Electro-Magneto-Thermoelastic homogeneous plate subjected to stress

This paper introduces the combined effect of electric field, magnetic field and thermal field on edge wave propagating in a homogeneous isotropic prestressed plate of finite thickness and infinite length. The dispersion relation of edge wave has been obtained by using classical dynamical theory of thermoelasticity. The phase velocity has been computed and shown graphically for various initial stress parameter, electro-magneto parameter, electric parameter and thermoelastic coupling parameter.

Examining Graphene Field Effect Sensors for Ferroelectric Thin Film Studies

We examine a prototype graphene field effect sensor for the study of the dielectric constant, pyroelectric coefficient, and ferroelectric polarization of 100-300 nm epitaxial (Ba,Sr)TiO3 thin films. Ferroelectric switching induces hysteresis in the resistivity and carrier density of n-layer graphene (n = 1-5) below 100 K, which competes with an antihysteresis behavior activated by the combined effects of electric field and temperature. We also discuss how the polarization asymmetry and interface charge dynamics affect the electronic properties of graphene.

Existence of solitary travelling waves in interfacial electrohydrodynamics

The propagation of waves on the surface of a fluid layer of finite depth is considered in the presence of a normal electric field, due to parallel electrodes at an arbitrary separation distance. The combined effect of electric field, gravity and surface tension is considered in the long-wavelength–small-amplitude limit. Travelling wave solutions are characterised in terms of the Froude number, an electric Weber number and a Bond number and conditions for the existence of solitary waves are determined in terms of these parameters.

Effects of hydrostatic pressure, temperature, electric field and aluminum concentration on the electronic states in GaAs/Ga1−xAlxAs concentric double quantum rings

Using the effective mass approximation and transfer matrix formalism the ground state energy of an electron in GaAs/Ga1−xAlxAs concentric double quantum rings is calculated taking into account the combined effects of electric field, hydrostatic pressure, temperature and aluminum concentration. The ground state energy dependences on the mentioned factors are presented for different values of the sizes of rings and electric field strength. It is found that the considered effects mainly depend on the dimensions of quantum rings.

Electronic states in a Pöschl–Teller-like quantum well: Combined effects of electric field, hydrostatic pressure, and temperature

The work is devoted to present a theoretical study of the influences of external probes, such as applied electric field and hydrostatic pressure, on the electron and hole states in a Pöschl–Teller quantum well. The calculations have been done in the framework of the variational method. The dependence of the ground state energy of an electron and/or hole confined in the quantum well has been obtained as a function of the applied electric field and hydrostatic pressure. Different values of the asymmetry parameters of the Pöschl–Teller potential as well as temperature have been considered. It is shown that as a result of the increase in the electric field there is an augment of the ground state energy, and also that by increasing the quantum well width the effects of applied electric field are strengthened. It is obtained from the calculations that the ground state energy is a decreasing (increasing) function of the hydrostatic pressure (temperature). It is found that in the high pressure regime the energy grows with pressure, which is a previously unknown result. In the case of holes, the energy is always an increasing function both of the pressure and the temperature. Besides, the behavior of the photoluminescence peak energies associated to transitions between the ground states of electrons and heavy holes in the system is also reported.

Combined effects of electric field and hydrostatic pressure on electron states in asymmetric GaAs/(Ga, Al) triple quantum dots

The combined effects of an in-growth direction applied electric field and hydrostatic pressure on the exciton binding energy and photoluminescence energy transitions are reported in this work for triple vertically coupled quantum dots. The calculations have been carried out within the effective mass approximation, and using a variational procedure. The results show that the exciton binding energy and the photoluminescence energy transitions are functions of external probes like the hydrostatic pressure and the applied electric field.