Influence Of External Electric Field Research Articles

Synergistic influence of external electric field on laser ablation in liquid: correlating nanoparticle synthesis and cavitation bubble dynamics

The present study aims to investigate the changes in the properties of nanoparticles (NPs) and cavitation bubble dynamics by applying an external electric field during laser ablation in liquid (LAL). Investigating electric field assisted laser ablation in liquid (EFLAL) is crucial since phenomena such as plasma charging effect and electrostatic pressure have important role in determining the size, shape, and crystallinity. of the NPs. With this motivation, the present study has been conducted with different electric fields of 0, 100, 500 and 1000 V cm−1 to probe the effect of an external electric field on the dynamics of EFLAL. The charging effect observed on NPs during cavitation bubble dynamics was also investigated at these field intensities. The size of NPs witnesses a reduction from ∼30 nm without electric field to ∼19 nm in presence of electric field. Also, a significant narrowing of the size distribution by over 4 times was observed in the presence of electric field. This clearly demonstrates that EFLAL can be used to obtain NPs with uniform size distribution. Moreover, NPs of different shapes have also been observed by varying the electric field intensities (100 and 1000 V cm−1). The effect of the external electric field on the dynamics of the cavitation bubble produced during EFLAL has been probed using shadowgraphy technique. It has been observed that the bubble size increases with the presence of an electric field. The estimation of the bubble pressure in the presence of an electric field has revealed that the implosion bubble pressure is significantly lower than pressure in the absence of the field. The results obtained for NPs have been correlated to the changes in bubble parameters in this work.

Influence of external electric field on properties of Cyclotriparaphenyl[6]carbon

Cyclotriparaphenyl[6]carbon is a hypothetical derivative compound of cyclo[12]carbon, in which three CC triple bonds are replaced by three benzene rings. Comprehensive investigations of influence of external electric field (EEF) on cyclotriparaphenyl[6]carbon have been performed from theoretical aspect in this work. The maximum appropriate applied electric field strength is 0.0265 a.u., electron detachment will occur when EEF exceeds this value. When the EEF is in the range of 0–0.0265 a.u., with the increase of EEF, the shape of cyclotriparaphenyl[6]carbon turns from a circle to oval, the HOMO-LUMO gap gradually decreases from 6.046 eV at 0 a.u. to 2.322 eV at 0.0265 a.u., and its absorption band extends to VL (visible light) region and near-infrared region little by little. When the EEF are 0.025 a.u. and 0.0265 a.u., its maximum absorption wavelengths are 1220.6 nm and 1383.5 nm, respectively. HOMA (Harmonic oscillator measure of aromaticity), AV1245 and electron localization function (ELF) calculation results indicate that cyclotriparaphenyl[6]carbon has no aromaticity in the EEF range of 0–0.0265 a.u.. The compound exhibitspromising potential forapplication inthefield of colordevelopingcompound materials.

The regulation of high-energy insensitive compound 2,6-diamino-3,5-dinitropyrazine-1-oxide by external electric field.

The influence of external electric fields (EEFs) on chemical substances has always been a hot topic in the field of theoretical chemistry research. 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is an energetic material with excellent comprehensive properties and enormous potential for application. This article explores the molecular structure, electronic structure, energy change, frontier molecular orbitals (FMOs) and density of states (DOS), UV-Vis spectra, and infrared spectra of LLM-105 under various electric field conditions. The results indicate that negative EEF can improve the stability of LLM-105, reflected in the initiation of changes in bond length and HOMO-LOMO gap. EEF has a significant impact on the electronic structure of LLM-105. The polarization of the electronic structure brings about a change in total energy, which is reflected in the analysis of energy changes. In addition, the external electric field will cause the frequency of the infrared spectra and the UV-Vis spectra to have different degrees of blue shift. The results of the analysis are helpful to understand the changes of energetic materials under the applied electric field. Based on the density functional theory (DFT), the structural optimization and energy calculation were carried out by using B3LYP/6-311G(d, p) and B3LYP/def2-TZVPP methods, respectively. After optimization convergence, vibration analysis was performed without imaginary frequencies to obtain stable configurations. Then, the molecular structure, electronic structure, energy changes, molecular orbital and density of states, UV-Vis spectra, and infrared spectra were analyzed.

Artificial synapses based on 2D-layered palladium diselenide heterostructure dynamic memristor for neuromorphic applications

The transformation of partially amorphous two-dimensional (2D) material layers represents a promising avenue for enhancing the reliability of heterostructure memristor devices and achieving high-density memory with synaptic characteristics. In this study, we investigate the advantages of aluminum oxide-based redox reactive layers integrated with 2D pentagonal palladium diselenide (PdSe2) layers, resulting in the realization of a reliable multilevel conductance memory controlled by DC and pulse voltages. Through careful analysis, we observed that the formation and rupture of conductive filaments related to oxygen vacancies were significantly controlled at the Al2O3/PdSe2 interface, where a mixed oxide of Al-PdSeOx was formed. This exciting phenomenon was further corroborated by comprehensive chemical analysis of the synapse structure as well as various synaptic behaviors, predominantly modulated by the facile movement of oxygen ions under the influence of external electric fields. Remarkably, our experimental results demonstrated improved endurance with multiple memory states achieved by judiciously altering the RESET voltage and SET current compliance, yielding an impressive memory window exceeding 10. Moreover, we successfully achieve a controlled transition from short-term to long-term memory through the application of identical and nonidentical consecutive pulse voltages. Inspired by biological synapses, our PdSe2-based artificial synapse exhibits biocompatible short-term plasticity, such as spike rate-dependent plasticity, paired-pulse facilitation, and experience-dependent plasticity, effectively mimicking the functionality of its biological counterparts. Notably, this biocompatible synapse also demonstrates great potential for visual memory processing, and multilevel 4-bit reservoir computing by demonstrating 5 × 4 digit image recognition thereby offering a distinct advantage for artificial neuromorphic applications.

Influence of External Electric Field on Optical Breakdown in High-Speed Flow

Influence of External Electric Field on Optical Breakdown in High-Speed Flow

Exploring the influence of external electric fields on the mechanical characteristics of zirconium disulfide nanosheets via density functional theory

The density functional theory is utilized to investigate elastic and plastic properties of zirconium disulfide (ZrS2) nanosheet subjected to a uniform external electric field up to 4 VÅ. In this respect, firstly, unit cell dimensions, bond lengths and bond angles are obtained by optimizing the unit cell of ZrS2nanosheet, and the most stable configuration is considered for the nanostructure accordingly. Then, by applying uniaxial and biaxial tensions on the nanosheet under a uniform external electric field, Young's and bulk moduli are computed, respectively. Finally, the applied strain is extended to the plastic region to evaluate the effect of external electric field on the first and second critical strains. It is shown that applying external electric field results in increasing Young's modulus of the nanosheet. However, the bulk modulus increases up to 2 VÅ and deceases afterwards. Besides, the first and second critical strains, which are respectively used to show the end of harmonic and inharmonic regions, decrease in the presence of the external electric field while the difference between them is not affected by the external electric field. Investigating the elastic and plastic properties of zirconium disulfide under an external electric field is important for both fundamental research and practical applications. It can help us develop new materials with tunable properties, optimize their performance in various devices, and contribute to the development of cutting-edge technologies

Dynamically tuning friction at the graphene interface using the field effect

Dynamically controlling friction in micro- and nanoscale devices is possible using applied electrical bias between contacting surfaces, but this can also induce unwanted reactions which can affect device performance. External electric fields provide a way around this limitation by removing the need to apply bias directly between the contacting surfaces. 2D materials are promising candidates for this approach as their properties can be easily tuned by electric fields and they can be straightforwardly used as surface coatings. This work investigates the friction between single layer graphene and an atomic force microscope tip under the influence of external electric fields. While the primary effect in most systems is electrostatically controllable adhesion, graphene in contact with semiconducting tips exhibits a regime of unexpectedly enhanced and highly tunable friction. The origins of this phenomenon are discussed in the context of fundamental frictional dissipation mechanisms considering stick slip behavior, electron-phonon coupling and viscous electronic flow.

Influence of external electric field on electronic structure and optical properties of β-Ga2O3: a DFT study.

The influence of different electric fields on the electronic structure and optical properties of β-Ga2O3 was studied by GGA+U method. The results show that appropriate electric field intensity can regulate the band gap of β-Ga2O3 more effectively to improve the photoelectric characteristics. The band gap value of intrinsic β-Ga2O3 is 4.865 eV, and decreases from 4.732 to 2.757 eV with the increase of electric field intensity from 0.05 to 0.20 eV Å-1. The length of the O-Ga bond along the electric field increases the fastest with the electric field intensity, and the distance between O and Ga reaches 2.52 Å when the electric field intensity is 0.20 eV Å-1. A new peak appears in the real and imaginary parts of the dielectric function for β-Ga2O3 in the low frequency region under the electric field, and the conductivity increases obviously. The optical absorption peaks induced by the electric field were observed in the wavelength range of 400-600 nm. The optical absorption of β-Ga2O3 is enhanced with an increase of electric field intensity, exhibiting a maximum value with the electric field of 0.15 eV Å-1. The electric field above 0.15 eV Å-1 causes a decrease of optical absorption intensity.

Effect of temperature on the dipole response, structural and dynamical properties of water under external electric fields

Water, as simultaneously the most intriguing and ubiquitous liquid on the planet, holds central relevance in our world – and displays a suite of fascinating anomalies. Of notable interest in this study is the leveraging of non-equilibrium molecular dynamics (NEMD) simulation to study the response of water molecules under the influence of external electric-fields while subjected to temperature changes. In particular, external static and oscillating electric fields with varying (r.m.s) intensities 0.05V/Å and 0.10V/Å and oscillating-field frequencies 50, 100 and 200GHz were examined to gauge the influence of supercooled and nearer-ambient temperature regions on water structure and interaction, dynamical properties, dipolar response, hydrogen-bond kinetics and lifetime. Interestingly, the impact of heating the system was accentuated with increase in the hydrogen-bond lengths, and A–D–H angles while the number of hydrogen-bonds reduced with increase in the temperature for all the fields conditions, although slight variations were observed under the influence of static and oscillating fields. Furthermore, as temperature increases, the increased rate of hydrogen-bond breakage influenced the rapid decay of hydrogen-bond lifetimes for zero- and static-field conditions, while molecular rotations caused by dipole-alignment response to the oscillating fields enhanced to a greater extent the mobility of the molecules, and also increased the rate of hydrogen-bond breakage and diffusivity due to the increased thermal motion. Moreover, the effect of increasing the temperature on the polarisation properties of the liquid weakened the hydrogen-bond network and also led to a decrease in the molecular and time response of the system’s dipole moment; higher temperature and field intensity invoked more rapid system dipolar alignment, in addition to the frequency relating to longer periods and greater intensity. With increasing temperature, the behaviour of system dynamics revealed shorter correlation times for zero-field conditions while oscillating-field with increased intensity revealed more rapid autocorrelation decay in comparison to those with reduced intensity. Indeed, the presence of much longer correlation time manifested by zero-field conditions in the supercooled temperature region evinced succinctly the lack of rotational motion that allows for more rapid decay time.

Electric Field‐Induced Phase Transition on HPX6 (X = C, Si, Ge, Sn) Monolayers

Herein, the electronic, thermoelectric, and optical properties of semimetallic HPX6 (X = C, Si, Ge, Sn) monolayers are systematically studied under the influence of external electric field in the framework of density functional theory. A band tuning has been achieved in these structures by the application of an external electric field of appropriate strength. It is predicted that Dirac cone splitting is nearly proportional to the external electric field strength. The modulation of electric properties induced by external field can alter the position of chemical potential in the band diagram and brings significant improvement in thermoelectric responses. The application of an external electric field significantly modulates the optical properties. The electric field‐induced HPX6 system provides better thermoelectric and optical response for nanodevice applications.

Влияние электрического поля на рекомбинационную люминесценцию коллоидных квантовых точек сульфида серебра

The paper studies the effect of external electric field on the optical properties of the spherical Ag2S quantum dots. Colloidal Ag2S nanoparticles passivated with 2-mercaptopropionic acid were obtained by photoinduced synthesis in the ethylene glycol. The nanoparticles shape and characteristic size were determined using the transmission electron microscopy. To analyze the external electric field influence, a series of samples was prepared based on the optically passive polymer film, where the nanoparticles were embedded. The films were placed between two glasses coated with the transparent electrodes based on the indium tin oxide (ITO). Intensity value of the external electric field created in such structures reached 500 kV/cm. The photoluminescence signal was registered using the CCD fiber spectrometer with spectral resolution of 1.16 nm. Spectrally resolved nanoparticles photoluminescence kinetics was measured by time-corre-lated counting of the separate photons. It was found that the presence of a field led to an increase in intensity and rate of the photoluminescence relaxation due to the surface states. This fact is related to acceleration of the free holes transportation to the recombination centers in the external electric field. It is shown that under long-term exposure to laser radiation with a wavelength of 405 nm and the average power of 5 mW, the nanocrystal photoluminescent properties could degrade, as it occurs due to formation of new centers of non-radiative recombination and photoionization of the quantum dots

Molecular Dynamics Simulation of the Influence of External Electric Fields on the Glass Transition Temperature of the Ionic Liquid 1-Ethyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide

We present the results of molecular dynamics simulations of the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C2C1im][NTf2] in the presence of external electric fields (EEFs) of varying strengths to understand the effects of EEFs on the glass transition temperature Tg. We compute Tg with an automated and objective method and observe a depression in Tg when cooling the IL within an EEF above a critical strength. The effect is reversible, and glasses prepared with EEFs recover their original zero-field Tg when heated. By examining the dynamics and structure of the liquid phase, we find that the EEF lowers the activation energy for diffusion, reducing the energetic barrier for movement and consequently Tg. We show that the effect can be leveraged to drive an electrified nonvapor compression refrigeration cycle.

Analyzing the combined influences of external electric field, impurity-location, in-content, and QW’s number on donor-impurity binding energy in multiple quantum wells with finite squared potential

Analyzing the combined influences of external electric field, impurity-location, in-content, and QW’s number on donor-impurity binding energy in multiple quantum wells with finite squared potential

Elucidating the alkene hydrogenation reaction based on cotton textile reduced graphene oxide under the influence of external electric field: Illustration of new noble method

The hydrogenation reaction of alkene is one of the most used industrial chemical process for various materials of daily life and energy consumption. This is a heterogeneous reaction and traditionally carried out by metallic catalysis. However, these conventional catalytic hydrogenations of alkene suffer from various setbacks such as catalyst poisoning, less recyclability and are environmentally unfriendly. Therefore, in recent years, researchers have been trying to develop the alternatives to metal catalysis hydrogenation of alkene. Heterogeneous catalysis under the external electric field is considered the future of green catalysis. In this paper, we report a comprehensive investigation dealing with the theoretical basis for simulating the phenomenon of heterogeneous catalysis, on a molecular level, under an external electric field. The illustration of the prospect as well as the effects of the mostly used catalytic systems, reduced graphene oxide, under the influence of external electric fields is provided. Moreover, a noble method of alkene hydrogenation reaction based on cotton textile reduced graphene oxide (CT-RGO) under the influence of an external electric field is introduced. The corresponding theoretical investigation was carried out within the framework of the density functional theory (DFT) method using first-principles calculations. The study has been carried out by elucidating DFT calculations for three different proposed catalytic systems, namely without electricity, with electricity and with an external electric field of 2 milli-Atomic unit. The obtained results indicate that adsorption energy of H2 on the CT-RGO surface is significantly higher when the electric field is applied along the bond axis, suggesting thereby that hydrogenation of alkene can be induced with CT-RGO catalyst support under external electric fields. The obtained results shed light on the effect of the external electricity field on the graphene-hydrogen complex, the activation energy of graphene radicals to achieve the transition states as well as the adsorption of the hydrogen atoms over the graphene surface. Altogether, the theoretical results presented herein suggested that the proposed catalytic system holds promise for facilitating the alkene hydrogenation under external electric fields.

Electronic Properties of Single‐Layer and Bilayer Graphene Nanoribbons

Herein, a tight‐binding description is utilized to investigate electronic structures and density of states of single‐layer (SL) and bilayer (BL) graphene ribbons with and without the influence of external electric fields. Analyses are implemented to reveal the similarity and difference among electronic properties of three types of structures (specifically SL and BL ribbons with AA and AB stackings). Moreover, both armchair and zigzag edge orientations are considered. It is indicated in the results that variation in electronic properties of these structures in the presence of external electric fields depends on both structural form and edge orientation. The following two points are demonstrated: 1) a transverse field has a significant effect on adjusting bandgap of the zigzag configurations, whereas a vertical electric field has a distinct impact on energy bands of armchair edge structures, and 2) among considered structures, AB‐stacking BL ribbons are invariably the structures that are most strongly influenced by external fields. Interestingly, AB‐stacking BL ribbons are also capable of enlarging bandgap with both edge terminations. Herein, an insight into how the electronic structure and charge distribution of both SL and BL graphene nanoribbons can be controlled not only in armchair but also in zigzag edge terminations using electric stimulants is provided by the results.

Properties of CF3SO2F under the influence of external electric field: A DFT study

With the deterioration of global greenhouse effect, CF3SO2F (Trifluoromethanesulphonyl Fluoride) has become an alternative gas of SF6 (Sulfur Hexafluoride). CF3SO2F has environmentally friendly characteristics and has been widely concerned. In this work, we analyze the electric field level of the discharge in the dielectric and the direction of the molecular intrinsic dipole moment. Density functional theory and time-dependent density functional theory are used to calculate the molecular structure parameters, dipole moments, frontier orbitals and excited states at corresponding electric field levels and in specific electric field directions. C2F5SO2F and C3F7SO2F, as by-products in the synthesis of CF3SO2F, are studied together to explore the influence of carbon atom number on molecular properties. As a result, the molecular structure is clearly changed under the electric field and the molecular bond length strongly depended on the electric field. The HOMO is mainly contributed by O atoms and the LUMO is mainly contributed by S atoms. When the electric field in the -z-axis direction is applied, the HOMO energies of molecules increase, especially for C3F7SO2F molecule, and the ionization potentials decrease correspondingly. The reduced ionization potentials facilitate the liberation of electrons from the molecule and the propagation of the streamer. The excitation energy of each molecule in each excited state decreases with the increasing of electric field intensity. Therefore, during the preparation process of CF3SO2F molecule, C3F7SO2F molecule should be reduced or removed as much as possible to prevent the reduction of dielectric insulation strength. The finding of this study is beneficial to the performance improvement and application research of CF3SO2F.

Regulation of external electric field on the high-energy polynitrogen compound 1,5-diaminotetrazole-4N-oxide.

The external electric field (EEF) tends to have a significant impact on chemicals, especially energetic materials. Molecular structure, electrostatic potential (ESP), electron density difference, density of states (DOS), and frontier molecular orbitals (FMOs) of 1,5-diaminotetrazole-4N-oxide (SYX-9) are calculated by density functional theory (DFT) at B3LYP/6-311G+(d, p) and M062X/def2-TZVP under external electric field. Calculated results reveal that EEF has definite influence on the trigger bond of SYX-9, especially in positive direction, and the shortening of the trigger bond caused by it can effectively reduce the sensitive of SYX-9. In addition, EEF has an effect on the electron density of SYX-9. The positive EEF can reduce the HOMO-LUMO gap. From the perspective of components of energy variation and the force on atoms, the factors of structural deformation are specifically investigated. The aromaticity of SYX-9 makes its structure stable under the influence of EEF, which is verified by the method of the iso-chemical shielding surface (ICSS).

The intensity and direction of the electric field effects on off-center shallow-donor impurity binding energy in wedge-shaped cylindrical quantum dots

• In the effective mass approximation, the finite difference method is adopted. • Electric field effect on donor binding energy in a wedge quantum dot is obtained. • The geometrical parameters effects (radius, height and opening) have been affected. • The six confined electronic states dependent on dot shape have been examined. Taking into account an infinite confinement potential, including the influence of external electric field applied in different directions, we have systematically examined the different factors that lead to changes in the ground state binding energy between the hydrogen impurity and the electron, which are confined in a wedge-shaped cylindrical quantum dot (WSCQD) of radius R , height H and azimuthal angle θ m . The resolution of the Schrödinger equation in three dimensions is achieved by the numerical finite difference method. The binding energy is calculated for several quantum dot geometry, various electric field direction, and different position of the impurity located on the first rectangular surface or inside the WSCQD. We have obtained that the direction of the electric field has an important influence on the binding energy of the off-center impurity. We have discussed in detail the weak effect of the radial electric field in the critical value of the WSCQD azimuthal angle θ m = 76.20 ∘ for R = 30 nm and H = 50 nm. The competition between the different effects, such as the electric field direction, the impurity position, and the no-symmetry of the WSCQD, on the electron-impurity distance, is physically interpreted in this paper. To make a more self-contained work, the finite confinement potential effects have also been discussed. Calculations have also been validated by using the finite element method.

Thermodynamic properties of perturbed monolayer PbBiI

In this paper, we theoretically investigate the influence of external electric field, Zeeman splitting field, and dilute charged impurity on the thermodynamic features of the PbBiI monolayer. Green’s function approach, the Born approximation, and the tight-binding model are employed to address these effects. We find the responses of the electronic heat capacity (HC) and Pauli spin paramagnetic susceptibility (PSPS) to the symmetry breaking originated from the presence of the perturbations. The results show that the electric (Zeeman) field leads to an increase (decrease) in the bulk gap of the system, resulting in a gapless phase at a critical Zeeman field. Correspondingly, HC and PSPS results confirm almost zero responses at the appeared critical Zeeman field. On the other hand, critical impurity characters emerge within the validity regime of the Born approximation. Finally, the combined effects of these perturbations are compared with the findings from the individual ones.

Effect of electric field on water free energy in graphene nanochannel

Graphene nanochannels and nanostructures have been of great interest to applications like nanofluidics and solar-thermal evaporation since nanoconfinement can lead to altered liquid properties. In this article, we employ molecular dynamics simulations combined with the free energy perturbation method to study the influence of external electric fields on the free energy of water molecules in graphene nanochannels. We observe a decrease in the water free energy difference (ΔG1−0=G0−G1, where 0 is the reference vacuum state and 1 is the solvated state) with the increasing electric field, suggesting that the application of an electric field may reduce the thermal energy needed to evaporate water from graphene nanochannels. Our analysis reveals that the reduction in free energy difference is related to more aligned water molecules along the electric field direction in the nanochannels, which leads to a decrease in the water inter-molecular potential energy and, thus, reduces the free energy difference.