Binding Energy Of Atom Research Articles

Effect of hydrogenation of carbon atom on its deposition on graphene

This article discusses the possibility of graphene functionalization by the deposition of carbon atoms with different degrees of hydrogenation and the effect of hydrogenation on the probability of precipitation using computer simulation. According to the results of computer simulation, the binding energy of the single carbon atom, methine, methylene and methyl is more than 1 eV. This corresponds to chemisorption, which means that the chemical bonds are generated due to unpaired valent electrons of the incident particles and defect-free graphene. Methane does not have unpaired valent electrons and in the range of investigated deposition energies its chemisorption on graphene is not observed. The free carbon atom with various degrees of its hydrogenation is considered: methane CH, methylene CH2, methyl CH3 and methane CH4. It is established that if the deposited particles C, CH, CH2 and CH3 form a bound state with graphene, these particles are located near the characteristic points with a different probability of location above graphene at these points. The processes of deposition of hydrogenated and non-hydrogenated carbon atoms with kinetic energies of 1.0, 1.2, 1.5, 2.3 and 3.1 eV on graphene are studied. It is found that the processes of deposition of non-hydrogenated and hydrogenated carbon atoms on defect-free graphene depend on the degree of hydrogenation of the carbon atom: the more hydrogenated the carbon atom is, the less its probability of chemisorption on graphene. Methane, as a fully hydrogenated carbon atom, does not chemisorb on graphene at deposition energies from 1 to 3.1 eV. It is also observed that the maximum probability of chemisorption of C, CH, CH2 and CH3 on graphene took place at deposition energy of about 2.3 eV.

The structure and properties of a carbon nanotube (7, 7) with a vacancy defect

Carbon nanotubes (CNTs) still draw great attention of researchers due to their possible use as anodes for lithium-ion batteries. The capacity of the anode for lithium ions is defined by the efficiency of diffusion of these ions to the adsorption centers located on the outer or inner surface of the nanotubes, as well as between the layers of multi-walled nanotubes. The inner surface can be accessed through the open ends of the tubes or defects in their frame. Moreover, the defects create more efficient adsorption sites than the surface of a perfect tube. This work presents the results of the ab-initio modeling of the lithium adsorption on a carbon nanotube (7, 7) with a vacancy-type defect. The simulation was carried out using density functional theory implemented in the SIESTA package. The Ceperley-Alder exchange-correlation functional and the DZP basis set were used. The formation energies of vacancy defects of two types were determined. Additionally, for each vacancy type, the binding energies of lithium atoms adsorbed inside and outside the CNT (7, 7) near the defect were calculated. These binding energies were shown to be up to twice bigger than on a perfect CNT. The enhancing effect of the vacancy on the CNT sorption activity was found to be wide-ranged: it was observed for adsorption sites in the first and second surroundings of the defect and even for sites located on the tube surface opposite to the defect.

Potassium methyl silicate (CH5SiO3Na) assisted activation and modification of alkali-activated-slag-based drying powder coating for protecting cement concrete

Alkali-activated materials (AAMs) have attracted extension attention as a promising material for protective coating, while its protective efficiency was limited due to inherent poor anti-permeability when subjected to aggressive marine environments. In this work, a novel strategy for hydrophobic modification of alkali-activated slag (AAS) by compositing potassium methyl silicate (PMS) to produce a protective coating for reinforced concrete was reported. Results show that PMS had an assisted-alkali activation, and could graft hydrophobic groups (–CH3) on the C-A-S-H/C-S-H gel chemical structure by condensation reaction. While PMS had a retard effect and reduced mechanical property due to the decreased binding energy of atoms and condensation degree of gel. The coating with 5 wt% PMS obtained a compacted microstructure, where gel production increased 26 %, porosity decreased 54 %, and harmless pore volume improved 14 %. The fabricated coating had excellent protective properties, which showed a bonding strength of 1.60 MPa, water contact angle of 128°, water absorption of 2.8 %, chloride ion penetration coefficient of 5.453 × 10-12 m−2/s, and the corrosion rate of reinforced rebar decreased by 97 %.

Relative Stability of Boron Planar Clusters in Diatomic Molecular Model.

In the recently introduced phenomenological diatomic molecular model imagining the clusters as certain constructions of pair interatomic chemical bonds, there are estimated specific (per atom) binding energies of small all-boron planar clusters Bn, n = 1–15, in neutral single-anionic and single-cationic charge states. The theoretically obtained hierarchy of their relative stability/formation probability correlates not only with results of previous calculations, but also with available experimental mass-spectra of boron planar clusters generated in process of evaporation/ablation of boron-rich materials. Some overestimation in binding energies that are characteristic of the diatomic approach could be related to differences in approximations made during previous calculations, as well as measurement errors of these energies. According to the diatomic molecular model, equilibrium binding energies per B atom and B–B bond lengths are expected within ranges 0.37–6.26 eV and 1.58–1.65 Å, respectively.

Δ‐SCF calculations of core electron binding energies in first‐row transition metal atoms

AbstractCore electron binding energies (CEBE) of nickel and copper atoms have been calculated using single‐configuration energy differences, the so‐called Δ‐self‐consistent field (Δ‐SCF) method. Basis set convergence has been examined for calculated L‐shell and M‐shell core electron binding energies, and a wide array of density functionals have been evaluated. Scalar relativistic corrections have been estimated using the popular Douglas‐Kroll‐Hess (DKH) approximation. While basis set convergence and functional dependence mirror the behavior reported in the literature for main group elements, the simplest Δ‐SCF calculations with pure Hartree‐Fock (HF) exchange and no correlation surprisingly outperform all density functionals in reproducing free‐atom CEBE values for Ni and Cu.

Mass & Quark Symmetry: Mass and Mass Cloud (The Yin Yang): Atom Binding Energy; Molecules Binding Energy; Binding energy between the nucleons in the nucleus; Particle Interaction Energy between particle and antiparticle; Quark Symmetry & Quark Confinement

The symmetry occurs in most of the phenomena explained by physics, for example, a particle has positive or negative charges, and the electric dipoles that have the charge (+q) and (-q) which are at a certain distance (d), north or south magnetic poles and for a magnetic bar or magnetic compass with two poles: North (N) and South (S) poles, spins up or down of the electron at the atom and for the nucleons in the nucleus In this form, the particle should also have mass symmetry. For convenience and due to later explanations, I call this mass symmetry or mass duality as follows: mass and mass cloud. The mass cloud is located in the respective orbitals given by the Schrödinger equation. The orbitals represent the possible locations or places of the particle which are determined probabilistically by the respective Schröndiger equation. For example and for the proton, the positive charge is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals or mass clouds. For the electron, the negative charge is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals or mass clouds. Besides, in the formation of the hydrogen atom, a part of the mass cloud of the proton interacts with the mass cloud of the electron, and the total mass-energy lost in this interaction is transformed into electromagnetic energy according to Einstein's equation: E=mc2 and the variant mass formula discovered and developed by myself: Giovanni Alcocer Variant Formulas. Therefore, the electron and proton are bound together in the hydrogen atom due to the electrostatic force between the two particles and the mass cloud of the electron and proton with some mass cloud lost in the interaction and converted to electromagnetic energy or photons. Then, it is right to assume this mass symmetry, since the electron and the proton in the interaction of the mass cloud lose mass but do not lose electric charge. In this form, it is justified the existence of a mass cloud. Therefore, the main function of the mass cloud is the binding energy. The mass cloud interaction generates binding energy between the electrons and the nucleus in the atom through the protons and between the nucleons in the nucleus: protons with protons, neutrons with neutrons, and protons with neutrons. The nuclear force between two nucleons is characterized by being strong and short-range. Also, it can be justified by the existence of the mass cloud: the mass clouds of nucleons within the nucleus interact with each other without any effect on the proton charge. In the same form and due to the quarks having mass and charge (and inclusive colors), the quarks have also the same mass symmetry: mass and mass cloud. Thus, the electrical charge is stored in the mass of the quarks and the mass cloud allows the confinement or the respective binding between quarks. Then, the following questions are explained and answered simply in this research article: why a particle does not exist with only one quark? why the quarks are confined to the nucleus? and which is the origin of the nuclear forces? On other hand, there are particles with two quarks (mesons), particles with three quarks (baryons) and then, it is very probable to find particles with more than three quarks (quaternions). This scientific research presents evidence of the existence of mass symmetry: mass and mass cloud and the interaction between the mass cloud of the particles (The Yin Yang Interaction) based on Einstein's equation and in the Variant Mass formula for the Electron in the atom discovered and demonstrated by myself where experimental results are detailed.

Scalar Field Model Provides a Possible Bridge between General Relativity and Quantum Mechanics

Herein is introduced a simple scalar field model derived from classical based kinetic energy, gravitational potential energy, and Special Relativity’s rest mass energy. By applying a classical orbit over the scalar field, relativistic effects are predicted. The scalar field is then applied to a classical model of the Hydrogen atom resulting in a relativistic effect equal to the binding energy of the Hydrogen atom. In addition, the model derives the fine structure constant due to the gravitational effect. The relativistic effects are then discretized in increments equal to the model’s gravitational induced constant. The discretization produces the Hydrogen atom spectral emissions and an angular momentum equal to Planck’s reduced constant. The model is not presented as a replacement for current theory, rather it is for inspection and illustration of how a simplistic model may offer a fundamental bridge between the more complex, time proven theories of General Relativity and Quantum Mechanics.

Atomistic Study on the Energetic and Mechanical Behaviors of Helium Bubble Nucleation and Growth in RAFM Steel

Helium produced by neutron irradiation is a crucial inducement to bring about the property of deterioration of structural materials served in a fusion reactor. To investigate the nucleation and growth behavior of helium bubbles in reduced activation ferritic/martensitic steels, which comprise one of the most promising candidate structural materials, the Molecular Statics method and the Metropolis Monte Carlo algorithm are combined to investigate the energetic and mechanical behaviors of HenVm clusters in α-Fe. The simulation results show that the vacancy and helium atom binding energy are inclined to reach a saturation state, i.e., 4.0 eV for the vacancy and 2.4 eV for the helium atom; however, the binding energy of self-interstitial atoms decreases to minus values at high helium-to-vacancy (He/V) ratios. The crossover of the binding energy curve of the helium and vacancy indicates that the equilibrium He/V ratio is 1.68 during the nucleation of helium bubbles. Meanwhile, the dissociation energy analysis indicates that the stable He/V ratio of the clusters is 1.3 at high temperatures. Moreover, the pressure analysis of the HenVm clusters indicates that the He/V ratio corresponding to their mechanical equilibrium state varies from 0.50 to 0.65 at 0 K. Furthermore, the analysis combined with the relevant experimental data of helium density in helium bubbles indicates that the actual He/V ratio of helium bubbles in the served materials is closely relevant to the irradiation condition, such as helium production rate, temperature, etc. The investigation results in this paper contribute to elucidate the microscopic process of helium bubble nucleation and growth and provides the energetic and mechanical parameters of small-sized helium bubbles with different sizes for large-scale simulation studies.

Dopant-dependent thermoelectric performance of indoloindole-selenophene based conjugated polymer

The development of organic conductors, which exhibit high electrical conductivity through chemical doping using non-acidic molecular dopants, has been challenging because of inefficient generation of free charge carriers. In this study, we synthesized a new conjugated polymer (CP) containing electron-donating indoloindole and biselenophene to devise an efficient doping platform. When the synthesized CPs were doped with electron acceptor (F4TCNQ) and Lewis acid (AuCl3) type dopants, both dopants realized high electrical conductivities (184 S·cm−1 for F4TCNQ and 283 S·cm−1 for AuCl3). Furthermore, the binding energies of the electron-donating atoms in the doped CPs and the degree of stabilization energy before/after doping indicated that Se and N atoms tended to interact more favorably with F4TCNQ and AuCl3, respectively. However, the Seebeck coefficient and power factor of the AuCl3-doped CP were lower than those of the F4TCNQ-doped CP, which was attributed to the larger amount of charge carriers generated by the AuCl3 dopant.

First-principles study of helium-vacancy complexes in Be12Ti

First-principles calculations have been conducted to study the stability of He-vacancy clusters and the trapping behavior of vacancies for He atoms in Be12Ti. We considered the various metastable microstructures of four types of He-vacancy clusters, and the most stable configurations were determined by the calculations of solution energy. Some He-vacancy clusters in Be12Ti have specific geometrical shape, and grow along specific crystal plane. For example, three types of He2V clusters (two He atoms trapped by vacancy) form dumbbell-shaped structure, three He atoms of He3V clusters (three He atoms trapped by vacancy) are located in the specific crystal plane. The solution energies of four types of clusters increase with the increase of number of He atoms, and the increasing rate is basically identical. The solution energies of HenVBe1 clusters are always the largest, and the solution energies of the HenVTi clusters are always the smallest, which mainly attribute to the larger vacancy volume and perfect spatial symmetry of Ti vacancies. The binding energies of a single He atom with HenV (n=0-3) clusters are all positive, and the segregation of He atoms on the inner surface of the vacancy is closer to the center of the vacancy, indicating that the He-vacancy has a stronger trapping ability for He atoms. The present research results provide a theoretical foundation of vacancy trapping mechanism for He atoms in Be12Ti, which is extremely important for the nucleation and growth mechanism of He bubbles in Be12Ti.

A First-Principles study of monolayer and heterostructure antimonene as potential anode materials for Magnesium-ion batteries

The development of magnesium-ion batteries requires anode materials with high capacity and fast kinetics. Based on first-principles calculations, outstanding magnesium capacities have been found for antimonene and an antimonene/graphene heterostructure. The results show that Mg atoms can adsorb on the surface of antimonene, and the most stable position is the site immediately above the center of the buckled honeycomb six-membered Sb ring. Compared with the heterostructure of antimonene, the monolayer has a relatively large binding energy for Mg atoms (−0.72 eV for antimonene and −0.70 eV for the heterostructure). Furthermore, we reveal that Mg ions diffuse more easily on the surface of the heterostructure than on the surface of the antimonene monolayer, and the lowest diffusion barrier is 45 meV. More importantly, the nanostructures based on antimonene have relatively large capacities of 735 mA h/g (as Mg1.67Sb) and 615 mA h/g (as Mg1.78SbC2.78). We expect that all these results can help clarify the mechanism of Mg storage in low-dimensional antimony materials and shed light on the design of magnesium-ion batteries.

Molecular dynamics simulations on the interactions between basal edge dislocation and point defects in magnesium at low temperature

In this work, we performed molecular dynamics (MD) simulations on the interactions between a basal edge < a > dislocation and point defects including vacancies and self-interstitial atoms in magnesium. Simulation results suggest that both self-interstitial atoms and vacancies have a blocking effect on dislocation motion, but the blocking effect of vacancies is much weaker than that of self-interstitial atoms. During interactions, self-interstitial atoms are absorbed and move with dislocation, and the edge dislocation climbs after absorbing self-interstitial atoms. In contrast, vacancies cannot be absorbed. To explain these observations, the binding energy and migration energy are calculated. The binding energy of both vacancies and self-interstitial atoms increases as they approach the dislocation core, seemingly indicating that they can be absorbed. However, the migration barrier of a vacancy is found to be about two orders in magnitude higher than that of a self-interstitial atom. Therefore, only self-interstitial atoms are absorbed, while vacancies cannot.

Benzobisthiazole-bridged white fluorescent emitting covalent organic framework for simultaneous mercury detection and removal

Mercury (Hg2+), a heavy metal ion, is considered one of the most toxic metals on earth and is widespread as an environmental pollutant. Various promising adsorbents have been developed with accessible chelating sites and high affinity for heavy metal ions. Herein, we utilized the advantages of covalent organic frameworks (COFs) and designed benzobisthiazole-bridged (BBT) fluorescent COFs (FCOFs) for Hg2+ sensing applications. The BBT-FCOF nanosheets has a π-π transition, effective electron transfer, and enhanced delocalization within the π orbitals of the BBT ring. It emits a white fluorescence enabling real-time detection of Hg2+ metal ions. The excellent sensing property of BBT-FCOF nanosheets was attributed to the high sensitivity towards Hg2+; this was confirmed by the x-ray photoelectron spectroscopy binding energy of sulfur and nitrogen atom in BBT-FCOF. The limit of detection of Hg2+ was 30 ppb, which is very low compared to other published methods. ICP-mass measurement also proved that BBT-FCOF nanosheets removed almost 99% of Hg and BBT-FCOF distribution coefficient (Kd) was calculated to be 5 × 105 g−1. The recyclability test proved that HCl effectively removed the adsorbed Hg2+ metal ions from BBT-FCOF nanosheets, making it a useful tool for real-time Hg2+ detection and removal from waste water.

Descriptor for positron binding to atoms

Systematic theoretical data of positron binding to atoms [C. Harabati, V. A. Dzuba, and V. V. Flambaum, Phys. Rev. A 89, 022517 (2014)] are handled by machine learning techniques. Despite the existence of unsystematic errors in the calculations, it becomes possible to identify, through bound-unbound classification, a descriptor as a function of just the polarizability and ionization potential of the isolated atoms. Details of the bonding mechanism appear to be less relevant and the binding seems to be described by simply these two atomic properties, with large predominance of the polarizability. The descriptor is shown to be useful in the discrimination of binding energies of atoms with approximately equal polarizabilities as well as to correct some possibly wrong energy data. Identified arguably wrong cases are withdrawn from the data set so that an adjusted simple relation for the binding energy as a function of the descriptor is obtained, allowing corrections and predictions of binding energies extended to atoms up to Rf (104), except lanthanides and actinides.

Electronic structural descriptors for hydrogen evolution and superior catalytic activity of graphene based structures

Defect and substrate introduced into catalyst are two feasible routes toward design of heterogeneous catalysts. It is vital to identify and understand the relationships among atomic, electronic structures and adsorbate binding ability of the catalytic surfaces. Herein, hydrogen evolution on different defect graphene with and without two-dimensional (2D) Mo2C substrate are selected as examples to explore the relationships. Three feasible electronic structural descriptors, including p and pz band centers of local atoms, electron transfer to local atoms, and deformation charge densities of composite structures, are exacted from electronic properties of the defect and substrate-supported graphene. It is found that those descriptors could predict the hydrogen binding energy quantitatively, and the hydrogen adsorption order qualitatively. The descriptor of local p and pz band centers originate from hybridization between the site atom and adsorbate. It is believed that the relationship of atomic structure, electronic structure and binding energy may be applied to other surfaces, and shed light on the nature origin of the structure–activity on electrochemistry. By tuning the descriptors by atomic structure of defect or substrate, suitable hydrogen binding ability and superior hydrogen evolution performance of graphene could be achieved. Several structures based on graphene own superior hydrogen evolution activity: the exchange current densities of S3NV1-G, S2NV2-G@Mo2C, N1-G@Mo2C, and N2-G@Mo2C are predicted to be 0.811, 0.963, 0.712, and 1.860 mA/cm2, respectively. Especially the last two ones, their negative interfacial binding energies, and the energy favorability of forming N1 and N2 defects, ensure their stabilities and easy syntheses in experiment, and enhance their potential applications.

On the Role of Nuclear Binding Energy in Understanding Cold Nuclear Fusion

The basic aim of this paper is to highlight the hidden energy source and understand the mechanism of the controversial and spectacular ‘cold nuclear fusion’ at nuclear energy scales. Following the concept of strong interaction, theoretically, fusion of proton seems to increase the binding energy of the final atom by 8.8 MeV. Due to Coulombic repulsion, asymmetry effect, pairing effect and, other nuclear effects, final atom is forced to choose a little bit of binding energy less than 8.8 MeV and thus it is able to release left over binding energy in the form of internal kinetic energy or external thermal energy. Thus, in cold fusion, heat release to occur, binding energy difference of final atom and base atom seems to be less than 8.8 MeV.

Electronic properties of Ptn (n = 4, 13, 15) nanoclusters decorated MoSe2 monolayer and its effect on C2H2 adsorption: First principles study

In this work, we investigated the electrical properties of Pt nanoclusters decorated MoSe2 monolayer by DFT calculation. The binding mechanism and electron characteristics of different Pt clusters (Pt4, Pt13, and Pt15) on MoSe2 surface were analyzed. By comparing the Pt clusters of different sizes, we believe that Pt clusters will not have a large binding size on MoSe2 surface due to the poor wettability brought by their high cohesion. For Pt15 and Pt13 clusters, the average binding energy of single Pt atom involved in Pt-Se bonding is −2.22 and −2.36 eV, respectively. In addition, an oversized Pt cluster may result in an antibonding orbit closer to the Fermi level. In terms of binding mechanism, the Se-4p and Pt-5d orbits bond at lower energy level of Se-4p, rather than directly with high-energy level Se-4p orbit. Pt13-MoSe2 also showed a good adsorption effect on C2H2 and made it become sp2 hybridized. The adsorption energy is −2.69 eV. The Pt13-MoSe2 may be a potential candidate for the hydrogenation of C2H2.

A first principles approach to the interactions of alkali metal atoms with carbon quantum dots

We investigate the interactions between alkali metal atoms (M = Li,Na,K) and carbon quantum dot models (CQDs) by density functional theory. For systems where Li and Na metal atoms are initially placed between two nearly planar CQDs, the interaction with the metal species induces a significant reorganization of the carbon network with the formation of macrocycles, which keep some similarity with fragments of carbon nanotubes. Binding energies of metal atoms to CQDs are significantly stronger than what is observed in pristine graphene and also in graphene nanoribbons. CQDs are characterized by high electron affinities. For a model with 32 carbon atoms [CQD32] the first and second electron affinities are 4.3 and 2.1 eV, respectively. Time dependent density functional (TDDFT) calculations for the electronic spectra of [CQD-M] complexes are compared with experimental information for similar carbon based structures. The results relying on TDDFT for [CQD-M] indicate that the enhancement of the absorption in the visible region in comparison with isolated [CQD] is related to excitations with a significant charge-transfer character.

Magnetic field amplification to gigagauss scale via hydrodynamic flows and dynamos driven by femtosecond lasers

Reaching gigagauss magnetic fields opens new horizons both in atomic and plasma physics. At these magnetic field strengths, the electron cyclotron energy ℏω c becomes comparable to the atomic binding energy (the Rydberg), and the cyclotron frequency ω c approaches the plasma frequency at solid state densities that significantly modifies optical properties of the target. The generation of such strong quasistatic magnetic fields in laboratory remains a challenge. Using supercomputer simulations, we demonstrate how it can be achieved all-optically by irradiating a micro-channel target by a circularly polarized relativistic femtosecond laser. The laser pulse drives a strong electron vortex along the channel wall, inducing a megagauss longitudinal magnetic field in the channel by the Inverse Faraday Effect. This seed field is then amplified up to a gigagauss level and maintained on a sub-picosecond time scale by the synergistic effect of hydrodynamic flows and dynamos. Our scheme sets a possible platform for producing long living extreme magnetic fields in laboratories using readily available lasers. The concept might also be relevant for applications such as magneto-inertial fusion.

Combined effects of the hydrostatic pressure and temperature on the self-polarization in a finite quantum well under laser field

In this study, the self-polarization and binding energy of the donor impurity atom in the laser field applied G a 1 − x A l x A s / G a A s quantum well are investigated under the combined influence of hydrostatic pressure and temperature. Variation of self-polarization and binding energy depending on temperature, hydrostatic pressure, impurity position, well width and laser field parameters are shown. Using the effective mass approximation, subband energy has been found by finite difference method and impurity energy has been found by variation method. Our results showed that hydrostatic pressure and temperature have a noticeable effect on the calculated self-polarization and binding energy in a quantum well under the effect of the laser field. We think that the results obtained will be useful in determining the physical properties of the quantum well under the influence of laser field, hydrostatic pressure and temperature. • The square quantum well is considered. • The effects of hydrostatic pressure and temperature on self-polarization have been calculated under laser field. • The variational and finite differences calculations have been performed. • Laser field parameter, hydrostatic pressure and temperature are important factor.