Effect Of External Electric Field Research Articles

Computational Investigation of Interaction of Titanocene Dichloride Anti-Cancer Drug with Carbon Nanotube in the Presence of External Electric Field

In this work, the interaction between titanocene dichloride, an anticancer drug, and carbon nanotube was studied at the B3LYP-D3/6-311G(d,p) level of theory. The external electric field effects on the total energy, dipole moment, electronic spatial extent (ESE), and the HOMO-LUMO gap of the Cp2TiCl2…nanotube molecule were studied. Also, the interaction energy values of the titanocene dichloride with carbon nanotube were calculated. We found good linear relationships between interaction energy, dipole moment, and ESE with external electric field strength.

Effects of external electric field on the sensing property of volatile organic compounds over Janus MoSSe monolayer: a first-principles investigation.

Janus 2D transition metal dichalcogenide (TMD) is a new generation 2D material with a unique asymmetric structure. This asymmetric structure (or out-off plane symmetric geometry) of Janus 2D TMD has been reported to yield tunable electronic properties through strain and electric field, which can also be applied in gas sensing. In this work, we performed DFT calculations to investigate the gas sensing property of cyclohexane and acetone on MoS2 and Janus MoSSe monolayers under external electric fields. Our results show that cyclohexane possesses slightly larger adsorption energy on pristine MoS2 and Janus MoSSe monolayers than acetone without external electric fields. After applying the external electric fields, the adsorption energy for cyclohexane on MoS2 shows no enhancement. However, the adsorption energy of acetone shows the most substantial enhancement on the Janus MoSSe monolayer. We found that the dipole moment orientations of adsorbates and the monolayer can strongly interact with the external electric fields. Hence, the combination of polar adsorbate and polar material, i.e., acetone and Janus MoSSe, demonstrates the most vital sensitivity under the applied bias. On the other hand, the non-polar adsorbate and non-polar material combination show a negligible effect on external bias. These findings can be applied to the design of gas sensors in the future through polar materials.

The external electric field effect on the charge transport performance of organic semiconductors: a theoretical investigation

We found that the external electric field can influence the structures and properties of organic semiconductors, and carefully considering the heteroatoms, symmetry and conjugation degree is possible to achieve directional mobility regulation.

External electric field effects on the σ-hole and lone-pair hole interactions of group V elements: a comparative investigation.

σ-hole and lone-pair (lp) hole interactions of trivalent pnicogen-bearing (ZF3) compounds were comparatively scrutinized, for the first time, under field-free and external electric field (EEF) conditions. Conspicuously, the sizes of the σ-hole and lp-hole were increased by applying an EEF along the positive direction, while the sizes of both holes decreased through the reverse EEF direction. The MP2 energetic calculations of ZF3⋯FH/NCH complexes revealed that σ-holes exhibited more impressive interaction energies compared to the lp-holes. Remarkably, the strengths of σ-hole and lp-hole interactions evolved with the increment of the positive value of the considered EEF; i.e., the interaction energy increased as the utilized EEF value increased. Unexpectedly, under field-free conditions, nitrogen-bearing complexes showed superior strength for their lp-hole interactions than phosphorus-bearing complexes. However, the reverse picture was exhibited for the interaction energies of nitrogen- and phosphorus-bearing complexes interacting within lp-holes by applying the high values of a positively directed EEF. These results significantly demonstrate the crucial influence of EEF on the strength of σ-hole and lp-hole interactions, which in turn leads to an omnipresent enhancement for variable fields, including biological simulations and material science.

The Effects on Electric Field and Hydrostatic Pressure on the Doped Properties in a Strained (In,Ga)N-GaN Coupled Quantum Wells

A variational approach is utilized to investigated the electron-impurity interaction in zinc-blende (In,Ga)N-GaN strained coupled quantum wells. The donor imputrity states are studied in consideration of the effects of hydrostatic pressure and external electric field. Our results indicate that the binding energy visibly depends on hydrostatic pressure, strain of coupled quantum wells, and applied electric field. The binding energy demonstrates a peak value with the reduction of the left-well width, and which displays a minimum value with the increment of the middle-barrier width. A decreasing behavior on the binding energy is also demonstrated when the right-well width enhances. Also the binding energy augments constantly with the increasing hydrostatic pressure. Besides, the dependency of the binding energy on variation of impurity position has been analyzed detailedly.

Stark shift and exciton binding energy in parabolic quantum dots: hydrostatic pressure, temperature, and electric field effects

ABSTRACT The temperature, hydrostatic pressure, and external electric field effects on the confined exciton in cylindrical quantum dots by considering a parabolic confining potential are investigated. The effects of these external perturbations on the binding energy and interband emission energy are calculated numerically by adopting the variational method within the effective mass approximation. Our findings indicate that the exciton binding energy and interband emission energy depend significantly on decreasing electric field, diminishing temperature, and enhancing the hydrostatic pressure. The contribution of the electric field on the binding energy becomes more important for wide axial parabolic quantum well. We have also shown that the Stark effect of exciton diminishes almost linearly with increasing hydrostatic pressure. Furthermore, the electric field and the quantum dot height lead to enhancing the Stark shift. The behaviour of the excitonic Stark shift as a function of the applied electric field proves the existence of a dipole moment. This physical parameter becomes important for the weak confinement regime.

Effect of external electric field on diffusivity and flash sintering of 8YSZ: A molecular dynamics study

The atomistic structural modification and ionic diffusivity in 8YSZ at elevated temperature with the presence of an external electric field (E-field) were investigated by molecular dynamics (MD) simulations. As an example, a sufficiently large system of atomic configuration for a bi-crystal ∑5(310)/[001] grain boundary (GB) model was studied. MD results show that the E-field promotes the formation of Frenkel pair defects. Notably, some Zr ions diffuse out of GB regions at E-field>∼500-1000V/cm, resulting in an “avalanche” of cation vacancies at GBs and reduction of GB space charge. Consequently, the diffusivities of cations and anions are enhanced in the 8YSZ system with the presence of E-field. The atomistic level understanding of E-field induced structural modifications and ionic diffusivities provide an in-depth insight to unravel the flash sintering mechanisms of ionic ceramics, especially the coupled thermal-field effect during the flash sintering process.

Geometrical Effects on Exchange Coupling in System of Near-Surface Donors and Quantum Dots

The value of exchange energy for near-surface double-donor and double-quantum dot structures under the effect of external electric field has been calculated using unrestricted Hartree–Fock method. The dependences of exchange energy on geometric parameters have been obtained. It has been found that the location of donor centers near the surface of the semiconductor leads to an increase in the exchange energy. Approximate formulas for the dependence of the exchange energy on the distance between the centers of quantum dots are suggested. It has been shown that exchange coupling control is less sensitive to electric field as compared to magnetic field, and electron density relocation at large electric fields should be taken into account when designing devices based on the structures under study.

Effects of External Electric Field on the Hydrolysis of Cisplatin: A Density Functional Theory Approach

In this study, hydrolysis of the anticancer drug cis-PtCl2(NH3)2 complex in the absence and presence of external electric field (EEF) has been studied using quantum mechanical methods. The B3P86 functional and basis sets of 6-311G(d,p) and LANL2DZ for main group element and Pt atoms, respectively, have been employed in these calculations. Two typical reactions involved in the complex hydrolysis include the first and second hydrolysis processes. We have tried to show how the total energy, barrier energy, thermodynamic, and kinetic parameters of cisplatin hydrolysis have been affected by the external electric field. In addition, variations of the structural parameters have been illustrated in the absence and presence of EEF. The structural-properties correlations between these parameters and strength of EEF have been provided. In addition, the barrier energy and reaction energy values of hydrolysis processes have been calculated by applying the isodensity polarizable continuum model (IPCM) for aqueous phase.

Electronic properties of a graphene nanotorus under the action of external fields

In this paper we study the properties of an electron trapped on a torus surface. We consider the influence of surface curvature on the spectrum and the behaviour of the wave function. In addition, the effects of external electric and magnetic fields were explored. Two toroid configurations were considered, namely, a torus-like configuration and a ring-like configuration both in agreement with experimental data. We also obtain the bound states and discuss the role of geometry on the Landau levels.

External Electric Field Effects on Electronic Properties of a Candidate Eco-friendly Biopolymer and Its Anticorrosive Properties in Acidic Media

In the theoretical/computational section of this work, external electric field effects (EF) on some electronic characteristics (at molecular/atomic scale) of the chitosan-like molecular (as biopolymer) system are studied. These results show that the mechanism of the variation of the HLG gap and consequently the electrical conductivity (I–V curves and molecular Joule-like effect) and thus local molecular electron transport efficiency ( $$ \Delta N $$ ) depend on the intensity of the applied external electric field. In addition, using atoms-in-molecules theory, the electronic response (such as atomic electron density, kinetic energy and viral force) of each atomic basin and each intra-molecular section to the EF are studied. Also, based on the molecular DOS diagram, the value of the global chemical softness, and thus the inhibition efficiency, of this molecular system is acceptable. Furthermore, in the experimental section of this work, the chitosan biopolymer was used as corrosion inhibitor in H2SO4 on aluminum (AA1005). The primary corrosion techniques like electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) was used to analyze the corrosion inhibition process. Also, EIS study reveals that corrosion is under kinetically controlled. The PDP proposed that chitosan composite is mixed-type corrosion inhibitor and inhibit corrosion by blocking the active sites presenting over the metal surface.

Nonradiative Relaxation Dynamics of a Cesium Lead Halide Perovskite Photovoltaic Architecture: Effect of External Electric Fields

Lead halide perovskites have attracted much attention as an active material in solar cells. In this first-principles study, we consider a cesium lead halide perovskite slab interfacing with electron transport and hole transport layers, relevant to the practical photovoltaic architecture. We apply external electric fields normal to the surface of the perovskite slab and explore the induced changes onto optoelectronic properties. It is found that the bandgap increases linearly and the conductivity diminishes exponentially with decreasing electric field strengths. Furthermore, we study the influence of electric fields onto nonradiative relaxation of photoexcited electrons and holes using the reduced density matrix in the formalism of Redfield theory. Our calculations provide relaxation rates and relaxation pathways, illustrating the mechanisms of modulations of electric field strengths onto charge carrier dynamics. Our results show that holes have longer lifetimes than electrons at various external electric fields. It is also found that the patterns of charge carrier dynamics depend on the direction of external electric fields. Specifically, in comparison with the system under zero field, our findings show that (i) the positive electric field facilitates the relaxation of electrons and holes and (ii) the negative electric field facilitates the relaxation of electrons but inhibits the relaxation of holes.

Controlling reaction rate of phase transfer hydrogenation of acetophenone by application of low external electric field

AbstractThe controllable mass transfer and reaction rate for phase transfer hydrogenation of acetophenone across a well‐defined boundary were investigated. The effect of solvent was found important and 1‐butanol exhibited the best performance among the five investigated homologous alcohol solvents, consistent with its higher solubility in water and greater dielectric constant. Initial reaction rates increased with increasing electric potential, consistent with enhanced mass transfer across the aqueous/organic boundary. At longer reaction times, deactivation was apparent. It correlated with increasing voltage and is ascribed to lower equilibrium concentration of reactive species at the interface. External control over reaction rate was demonstrated by switching the applied electric potential over the course of the reaction. Effects of external electric field on enantioselectivity were also explored with reversal field direction. The changes correlate with catalyst decomposition.

Investigation of a Liquid-Phase Electrode for Micro-Electro-Discharge Machining.

Micro-electro-discharge machining (μEDM) plays a significant role in miniaturization. Complex electrode manufacturing and a high wear ratio are bottlenecks for μEDM and seriously restrict the manufacturing of microcomponents. To solve the electrode problems in traditional EDM, a µEDM method using liquid metal as the machining electrode was developed. Briefly, a liquid-metal tip was suspended at the end of a capillary nozzle and used as the discharge electrode for sparking the workpiece and removing workpiece material. During discharge, the liquid electrode was continuously supplied to the nozzle to eliminate the effects of liquid consumption on the erosion process. The forming process of a liquid-metal electrode tip and the influence of an applied external pressure and electric field on the electrode shape were theoretically analyzed. The effects of external pressure and electric field on the material removal rate (MRR), liquid-metal consumption rate (LMCR), and groove width were experimentally analyzed. Simulation results showed that the external pressure and electric field had a large influence on the electrode shape. Experimental results showed that the geometry and shape of the liquid-metal electrode could be controlled and constrained; furthermore, liquid consumption could be well compensated, which was very suitable for µEDM.

Colloidal brass nanoparticles produced by pulsed laser ablation in deionized water and the effect of external electric field on particle size characteristics and ablation rate

In this paper, we report production of colloidal brass particles by pulsed laser ablation in deionized water in the presence of external electric field (EEF). The colloidal brass particles have sizes ranging from nano-scale to submicron sizes. The ablation rate and particles production yield in the presence of EEF was studied. The paper also presents the results of investigations on surface plasmon resonance (SPR), and size distributions of particles. These investigations show that EEF influences the ablation process and increases the particle concentrations. According to results, applying EEF leads to rise of nanoparticles (NPs) yield and decrease of their average size. According to our results, a blue shift occurs for SPR when EEF is applied.

Structural and functional changes of the protein β-lactoglobulin under thermal and electrical processing conditions

In the present study we have tried to explore the effect of static external electric field of strength 3.0 V/nm on the conformational changes adopted by the protein β-lactoglobulin. We have chosen different temperatures viz. 300 K, 400 K and 450 K to evaluate the temperature dependent effect of electric field. We have observed that combined effect of high temperature and static external electric field show significant changes on the structural conformation of the protein which in turn may affect the functional properties of the protein. Calculations of root mean square deviations reveal that both helical and β-sheet regions of the protein are noticeably affected at high temperature. We have used solvent accessible surface area (SASA) and dipole moment values to explain that there is changes in hydrophobicity of the protein surface due to presence of external electric field. The study reveals that electric field in combination with high temperature can be used to alter the conformation of the protein and the effect of external electric field is more pronounced at high temperature than that of low temperature. The study provides a better understanding of the conformational changes adopted by the protein under the stress of external electric field and high temperature and provide guidance to choose optimum conditions for processing without loss of nutritional properties.

Effects of external electric and magnetic fields on the linear and nonlinear optical properties of InAs cylindrical quantum dot with modified Pöschl-Teller and Morse confinement potentials

The theoretical investigation of linear and third-order nonlinear absorption coefficients and refractive index changes in the cylindrical quantum dot with two models of confinement potentials in axial direction, namely, modified Pöschl-Teller and Morse potentials, and parabolic potential in radial direction, have been considered in the presence of external electric and magnetic fields. The selection rules for intraband transitions have been obtained for both potentials in the presence and absence of external fields. The behavior of linear, nonlinear and total absorption spectra have been observed for different values of temperatures for both potentials taking into account electron population on energy levels. The effect of change in the direction of electric field on the absorption spectra have been investigated, and the asymmetric and symmetric characters of these potentials manifest themselves differently: the peak positions of absorption lines for Morse potential undergo blue and red shifts compared to the case when the external electric field is absent, while for the case of modified Pöschl-Teller potential the absorption lines have only red shift. The same dependencies have been obtained for refractive index changes for both potentials. The second and third harmonic generation coefficients as a function of the photon energy have been plotted both in the absence and presence of external fields.

Molecular dynamics study of sessile ionic nanodroplet under external electric field

Effect of external electric field and surface temperature on the dynamics of a sessile ionic nanodroplet has been investigated using classical molecular dynamics (MD) simulations. The study investigates the spreading, evaporation and deformation behavior of a salt-water nanodroplet on a solid Pt surface in the presence and absence of external electric field. Varying the intensity and direction of the external electric field, a series of MD simulations were carried out considering a moderate concentration of ionic solution to understand these phenomena at molecular level. In the presence of salt ions, effect of hydration becomes more dominant which resists the deformation of the nanodroplet. It was also found that vertical electric field leads to the formation of nanobridge/column like structures beyond some critical field intensities. In addition to the electro-evaporation, the present study probes the effect of surface temperature on the evaporation and spreading process of the sessile ionic nanodroplet.

Effect of external electric field on hydrogen-related defect in amorphous silica

The effect of external electric field on the interaction between interstitial hydrogen atoms and defect-free amorphous silica (a-SiO2) is studied by means of the reactive force field (ReaxFF) molecular dynamics (MD) simulation and density functional theory (DFT) simulation. We investigate the effects of the hydrogen-atom-hopping and the evolution of interstitial hydrogen atom in a-SiO2 on two kinds of hydrogen-related defect, hydroxyl E' center and [SiO4/H]0 center. We find that electric field enhances hydrogen-atom-hopping and the generation of hydroxyl E' center, while does not have significant influence on the formation of [SiO4/H]0 center. Moreover, hydroxyl E' center is more stable under electric field. We note that more unstrained Si-O bonds (shorter than 1.7 Å) become active in the reaction of the interstitial hydrogen atom with a-SiO2 under electric field. These effects of electric field on a-SiO2 lead to an increasing of the hydroxyl E' centers, which gives rise to the degradation in performance of microelectronic devices. These results provide a better understanding of the behaviors of hydrogen atoms and the generation mechanism of hydrogen-related defects in a-SiO2, especially under external high electric field.

Tunable electronic properties of silicene based heterojunctions with ultrathin high-к La2O3 gate dielectric

The silicene/La 2 O 3 heterojunctions envision promising applications in novel integrated functional nanodevices . The electronic properties of silicene , La 2 O 3 , and silicene/La 2 O 3 heterojunctions are investigated by first-principles calculations. The silicene/La-terminated La 2 O 3 heterojunction presents a 1.753 eV band gap, which is desired for silicene-based semiconductor devices. The effects of biaxial strain and external electric field are studied for the band structure of silicene/La 2 O 3 heterojunction. The band gap values of silicene/La 2 O 3 heterojunction could be effectively modulated. These findings indicate the potential application prospects of silicene-based field effect transistor with La 2 O 3 gate dielectric in nanoscale devices. • The silicene/La-terminated La 2 O 3 heterojunction presents a desired 1.753 eV band gap. • External electric field induces semiconductor–metal transitions. • The band gap values of silicene/La 2 O 3 heterojunction could be effectively modulated by biaxial strains. • The silicene/La 2 O 3 heterojunction has a potential application in silicene-based MOSFETs.