scholarly journals Quasi-planar elemental clusters in pair interactions approximation

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 617-620 ◽  
Author(s):  
Levan Chkhartishvili
Keyword(s):  
Binding Energy ◽  
Relative Stability ◽  
Dangling Bonds ◽  
Coordination Numbers ◽  
Theoretical Frame ◽  
Pair Interactions

AbstractThe pair-interactions approximation, when applied to describe elemental clusters, only takes into account bonding between neighboring atoms. According to this approach, isomers of wrapped forms of 2D clusters – nanotubular and fullerene-like structures – and truly 3D clusters, are generally expected to be more stable than their quasi-planar counterparts. This is because quasi-planar clusters contain more peripheral atoms with dangling bonds and, correspondingly, fewer atoms with saturated bonds. However, the differences in coordination numbers between central and peripheral atoms lead to the polarization of bonds. The related corrections to the molar binding energy can make small, quasi-planar clusters more stable than their 2D wrapped allotropes and 3D isomers. The present work provides a general theoretical frame for studying the relative stability of small elemental clusters within the pair interactions approximation.

scholarly journals Relative stability of planar clusters B11, B12, and B13 in neutral- and charged-states

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Levan Chkhartishvili
Keyword(s):  
Binding Energy ◽  
Relative Stability ◽  
Energy Criterion ◽  
Nanostructured Coating ◽  
Neutron Absorption ◽  
Coating Materials ◽  
Boron Cluster ◽  
Boron Clusters ◽  
Planar Structures ◽  
Electromagnetic Radiations

Theoretically, within the diatomic model, there is studied the relative stability of most abundant boron clusters B11, B12, and B13 with planar structures in neutral, positively and negatively charge-states. According to the specific (pet atom) binding energy criterion, B12+ (6.49 eV) is found to be the most stable boron cluster, while B11– + B13+ (5.83 eV) neutral pair is expected to present the preferable ablation channel for boron-rich solids. Obtained results would be applicable in production of boron-clusters-based nanostructured coating materials with super-properties such as lightness, hardness, conductivity, chemically inertness, neutron-absorption, etc. making them especially effective for protection against cracking, wear, corrosion, neutron- and electromagnetic-radiations, etc.

scholarly journals Relative stability of planar clusters B11, B12, and B13 in neutral- and charged-states

2018 ◽  
Author(s):  
Levan Chkhartishvili
Keyword(s):  
Binding Energy ◽  
Relative Stability ◽  
Energy Criterion ◽  
Nanostructured Coating ◽  
Neutron Absorption ◽  
Coating Materials ◽  
Boron Cluster ◽  
Boron Clusters ◽  
Planar Structures ◽  
Electromagnetic Radiations

Theoretically, within the diatomic model, there is studied the relative stability of most abundant boron clusters B11, B12, and B13 with planar structures in neutral, positively and negatively charge-states. According to the specific (pet atom) binding energy criterion, B12+ (6.49 eV) is found to be the most stable boron cluster, while B11– + B13+ (5.83 eV) neutral pair is expected to present the preferable ablation channel for boron-rich solids. Obtained results would be applicable in production of boron-clusters-based nanostructured coating materials with super-properties such as lightness, hardness, conductivity, chemically inertness, neutron-absorption, etc. making them especially effective for protection against cracking, wear, corrosion, neutron- and electromagnetic-radiations, etc.

scholarly journals Visualization of magnesium and rubidium ion hydration in sulfocationite using quantum chemical calculation

2021 ◽  
Vol 65 (6) ◽  
pp. 692-701
Author(s):  
V. S. Soldatov ◽  
T. V. Bezyazychnaya ◽  
E. G. Kosandrovich
Keyword(s):  
Binding Energy ◽  
Ab Initio Calculation ◽  
Molecular Layer ◽  
Binding Energies ◽  
Magnesium Ion ◽  
Water Molecules ◽  
Chemical Calculation ◽  
Ion Hydration ◽  
Coordination Numbers ◽  
Comparable Size

Based on the data of ab initio calculation of the structure of (RSO3)2Mg (H2O)18 and (RSO3Rb)2(H2O)16 clusters, which simulate the structure of swollen sulfostyrene ion exchangers in the corresponding ionic forms and a water cluster of comparable size, the numbers of water molecules directly bound to cations and their coordination numbers, including the oxygen atoms of the sulfonic groups linked to the cation, were calculated. It is shown that the first molecular layer around the magnesium ion is formed from water molecules with the highest binding energy with the cluster, and around the rubidium ion – from the molecules of the nearest environment with the lowest binding energies. This is explained by the fact that the transfer of water molecules from its volume to magnesium hydrate is energetically favorable, but not to rubidium hydrate. Therefore, the magnesium ion builds its hydrate mainly from water molecules with the highest binding energy in order to obtain the greatest energy gain, and the rubidium ion – from molecules with the lowest energy, which provides the smallest energy loss.

THE ORGANIC LED SURFACE: A SYNCHROTRON RADIATION PHOTOEMISSION STUDY

2007 ◽  
Vol 14 (03) ◽  
pp. 377-385 ◽  
Author(s):  
TUN-WEN PI ◽  
T. C. YU
Keyword(s):  
Synchrotron Radiation ◽  
Binding Energy ◽  
Elevated Temperatures ◽  
Core Level ◽  
Pyridyl Ring ◽  
Dangling Bonds ◽  
Surface Electronic Structure ◽  
Photoemission Study ◽  
Synchrotron Radiation Photoemission ◽  
Original Component

Tris(8-hydroxyquinolato) aluminum ( Alq 3), a prototypical molecule for organic light-emitting devices, has been studied via synchrotron radiation photoemission to investigate (1) the surface electronic structure of the molecules at room temperature and at elevated temperatures, (2) adsorption onto the inorganic Si (001)-2×1 surface, and (3) doping with the alkaline metal Mg . For case (1), three chemical environments of carbon are resolved. Moreover, the shake-up satellite structures are detected in all the N 1s, C 1s, O 1s, and Al 2p core-level spectra, but with different magnitudes. Annealing allows for a charge redistribution within Alq 3 itself. As to case (2), the organic molecules not only passivate the dangling bonds, but also rupture the dimer bonds. The wave function of the surface dangling bonds and of the pyridyl side of an 8-quinolinol ligand overlaps greatly so that charge is polarized towards, the organic adlayer. However, the polarization diminishes at greater coverage. With regard to case (3), the N 1s core-level spectra appear as an Mg -induced charge-transfer component with a binding energy lower than the original component. This new component grows gradually in intensity with increasing concentration of the dopant. Moreover, Mg also affects the O 1s core, as manifested by a component lying at a +1.09 eV higher binding energy than the original component. The Mg 2p core-level spectra, although rather broad, exhibit a shift toward a lower binding energy with increasing Mg vapor. Upon examining all these experimental results, we propose that Mg in the surface Alq 3 molecules forms clusters. Each cluster attaches to a pyridyl ring, affecting not only the nitrogen atom at that ring, but also the oxygen atom in the adjacent phenoxide ring. The depleted charge in the affected oxygen then flows about its adherent ligand and resides on the pyridyl ring at that ligand, resulting in a high Alq 3 anion state.

The Nature of the Surface of a Metal-Metalloid Metallic Glass

1986 ◽  
Vol 82 ◽  
Author(s):  
W. E. Brower ◽  
P. Tlomak ◽  
W. Kowbel ◽  
S. J. Pierz
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Metallic Glass ◽  
Relative Stability ◽  
Atomic Scale ◽  
Coordination Numbers ◽  
Quenched Glass

ABSTRACTThe surface of a metallic glass has been characterized at the atomic and microstructural levels. On the atomic scale, the glassy surface hal been previously characterized via a model which allows the calculation of surface coordination numbers and the fractal dimension. Catalytic experiments and LEIS measurements appear to confirm the model's prediction of surface roughness on the atomic scale. In this work, the glassy surface has been characterized on the microstructural level via RHEED patterns. In addition, the fresh glassy surface produced by comminution of Fe-B glass has been characterized with respect to the relative stability of the comminuted glass as compared to as-quenched glass.

Controlled modulation of the binding energy of impurity states in a quantum-well system

1996 ◽  
Vol 166 (4) ◽  
pp. 447-448 ◽  
Author(s):  
Vladimir I. Belyavskii ◽  
Yurii V. Kopaev ◽  
N.V. Kornyakov
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Impurity States

Arguing for Design Thinking Interventions as a Form of Artistic Interventions

2016 ◽  
Vol 10 ◽  
pp. 40-47
Author(s):  
Ulla Johansson Sköldberg ◽  
Jill Woodilla
Keyword(s):  
Organizational Change ◽  
Design Thinking ◽  
Organizational Innovation ◽  
Frame Of Reference ◽  
Full Potential ◽  
Artistic Process ◽  
Theoretical Frame ◽  
Artistic Interventions ◽  
Innovation And Change ◽  
Empirical Material

Drawing on data from two projects where artists used their artistic competence as organizational change facilitators, we argue for a theoretical coupling of the discourse(s) of design thinking to research streams within art-and-management. The artistic dimension of design, the practice perspective and the artistic process should be considered if we are to understand the full potential of design thinking for companies. This paper describes two artistic intervention projects that highlight valuable ways artists can contribute to organizational innovation and change.  We begin with the theoretical frame of reference and a short methodological statement, followed by the empirical material.  In the analysis section we point to ways in which such interventions are similar to ones led by designers when we consider the designer’s process as individualized and contextualized.  Finally, we draw conclusions.

Photoconductivity in Vacuum Deposited Films of Silicon-Based Polymers

1996 ◽  
Vol 444 ◽  
Author(s):  
H. Okumoto ◽  
M. Shimomura ◽  
N. Minami ◽  
Y. Tanabe
Keyword(s):  
Charge Transfer ◽  
Chemical Modification ◽  
Electronic Transport ◽  
Hole Transport ◽  
Electron Acceptors ◽  
Oxygen Atmosphere ◽  
Dangling Bonds ◽  
Silicon Based ◽  
Deposited Films

AbstractSilicon-based polymers with σconjugated electrons have specific properties; photoreactivity for microlithography and photoconductivity for hole transport materials. To explore the possibility of combining these two properties to develop photoresists with electronic transport capability, photoconductivity of polysilanes is investigated in connection with their photoinduced chemical modification. Increase in photocurrent is observed accompanying photoreaction of poly(dimethylsilane) vacuum deposited films. This increase is found to be greatly enhanced in oxygen atmosphere. Such changes of photocurrent can be explained by charge transfer to electron acceptors from Si dangling bonds postulated to be formed during photoreaction.

Metastable Defects in the Amorphous Silicon-Germanium Alloys

2003 ◽  
Vol 762 ◽  
Author(s):  
J. David Cohen
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Dangling Bonds ◽  
Annealing Behavior ◽  
Fundamental Properties ◽  
Silicon Materials ◽  
Salient Features ◽  
The Individual ◽  
Amorphous Silicon Germanium ◽  
Silicon Germanium Alloys

AbstractThis paper first briefly reviews a few of the early studies that established some of the salient features of light-induced degradation in a-Si,Ge:H. In particular, I discuss the fact that both Si and Ge metastable dangling bonds are involved. I then review some of the recent studies carried out by members of my laboratory concerning the details of degradation in the low Ge fraction alloys utilizing the modulated photocurrent method to monitor the individual changes in the Si and Ge deep defects. By relating the metastable creation and annealing behavior of these two types of defects, new insights into the fundamental properties of metastable defects have been obtained for amorphous silicon materials in general. I will conclude with a brief discussion of the microscopic mechanisms that may be responsible.

Excitonic quasimolecules containing of two quantum dots

2016 ◽  
pp. 4024-4028 ◽  
Author(s):  
Sergey I. Pokutnyi ◽  
Wlodzimierz Salejda
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Exchange Interaction ◽  
Coulomb Interaction ◽  
Silicate Glass ◽  
Glass Matrix ◽  
Silicate Glass Matrix

The possibility of occurrence of the excitonic  quasimolecule formed of spatially separated electrons and holes in a nanosystem that consists  of  CuO quantum dots synthesized in a silicate glass matrix. It is shown that the major contribution to the excitonic quasimolecule binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes.

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