S. S Moliver | Alikhanov Institute for Theoretical and Experimental Physics (original) (raw)
Papers by S. S Moliver
The electron structures of two forms of the grafted carbon dimer for the (8, 0) zigzag nanotube w... more The electron structures of two forms of the grafted carbon dimer for the (8, 0) zigzag nanotube were calculated by the semi-empirical quantum-chemistry method applied to the supercell model. If the dimer adsorbs above the center of the tube's hexagon (h-grafting), it performs the topochemical transformation of the tube, according to the Stone–Wales scheme of inverse kind. B-grafting is a chemisorption above tube's bond, it is energetically lower, than h-grafting. Atomic structure of b-grafting is a splitted di-interstitial. Measuring the electronic density of states in the upper valence bandhas been shown to make it possible to distinguish between pure and grafted nanotubes, as well as between band h-graftings.
![Research paper thumbnail of Investigation of fullerene[60] films on polymer substrates](https://attachments.academia-assets.com/41136029/thumbnails/1.jpg)
](Semiconductors, 2003
[60]Fullerene solid films deposited by vacuum sublimation on polymer substrates were studied by m... more [60]Fullerene solid films deposited by vacuum sublimation on polymer substrates were studied by methods of X-ray 23 diffraction structure analysis, IR optical transmission, and laser-excited photoluminescence (PL) spectroscopy. Mechanism of 24 good chemical adsorption to centers with unsaturated bonds C=N and C≡N was on trial. Room-temperature PL band at 1.78 25 eV has its origin in interface chemical bonds or molecular complexes, that arise most probably according to Diels-Alder 26 cyclo-addition of fullerene and polymer molecules. 27
n at n=3, 6](https://attachments.academia-assets.com/41096711/thumbnails/1.jpg)
](Physics of the Solid State, 2001
Earlier, we found the energies of formation and the electron band structures of the fullerene mol... more Earlier, we found the energies of formation and the electron band structures of the fullerene molecule C 60 and its methylated and hydrogenated chemical derivatives with saturated r 6 bonds of the type C 60 (CH 3 -r 6 -H) n with n from 1 to 6. Based on the self-consistent molecular-orbital method, we found the energies of singlet and triplet excitations for each molecule by the ∆ SCF technique. We compared the electron structure of the fullerene molecule with experimental data and other theoretical calculations and showed that the semiempirical quantum-chemical technique used in our work satisfactorily explains the experimental photoluminescence spectra of fullerene-containing star-shaped polystyrenes. Partial or complete removal of the dipole inhibition for the transitions in isomers that are formed upon chemical saturation of double bonds makes it possible to follow changes in the electron structure of the p π shell of the fullerene molecule by spectroscopic techniques. Specific optical spectra of the first excited singlet states (spectra of absorption, luminescence, and excitation of luminescence) as well as phosphorescence of the first spin-triplet state are described. © 2001 MAIK "Nauka/Interperiodica".
![Research paper thumbnail of Structure and Optical Properties of C[60] Films on Polymer Substrates](https://attachments.academia-assets.com/41106228/thumbnails/1.jpg)
](Microelectronic Engineering, 2003
The results of investigations of the structure and optical properties of films of fullerene C 60 ... more The results of investigations of the structure and optical properties of films of fullerene C 60 are reported. The films were obtained by vacuum thermal evaporation on substrates from heat-resistant polymers (polyacrylonitrile and cyclized polyacrylonitrile in composition with polyimide). The structure of C 60 films was determined by X-ray diffractometry. In all diffraction patterns of fullerene films, their structure manifests itself through reflections from the (111), (220), and (311) planes. Cubic C 60 films were obtained by fullerene deposition at substrate temperatures as high as 200 ° C. Atomic force microscopy of the film surface revealed the existence of a laminated structure. The infrared (IR) transmission spectra are indicative of the presence and constancy of the position of characteristic bands of C 60 (527, 576, 1183, and 1428 cm -1 ) for all fullerene films. The investigation of photoluminescence of fullerene films revealed bands whose energy position both exceeded typical values for molecular C 60 or fell below these values. This circumstance is caused by the interaction between the electron π systems of C 60 and the polymer substrate at the heterointerface, as well as by the photopolymerization reaction of fullerene under the effect of high-energy laser radiation and by the emergence of trap centers in the films.
It is shown that, in Auger-electron spectra of three-dimensional semimetal graphite and two-dimen... more It is shown that, in Auger-electron spectra of three-dimensional semimetal graphite and two-dimensional graphite (a zero band-gap semiconductor), an energy gap should be observed between the thresholds (edges) of the forward and inverse processes (threshold gap). In the one-electron approximation, this gap is zero, since the threshold for the Auger spectrum of the forward process is the minimum hole energy in the valence band, while the threshold for the spectrum of the inverse process is the minimum energy of conduction electrons. Inclusion of the electron correlation at the Fermi surface within the quantum-chemical approximation of a single open electron shell for multiplet structures of the restricted Hartree-Fock method makes it possible to determine the threshold gap as 1.5 eV for a 48-atom cyclic model of three-dimensional graphite and as 2.0 eV for a 24-atom model of two-dimensional graphite. The threshold gap does not contain the Fermi energy, in contrast to the Auger spectrum thresholds, where (4.0 eV -ε F ) for the forward Auger spectrum (holes) and ( − 1.1 eV + ε F ) for the inverse spectrum (conduction electrons), the sum of which gives this gap. The results of calculations for the forward Auger spectra of three-dimensional graphite (including the conclusion that electron correlation of holes in the top valence bands is weak in the Auger process) are shown to agree with the experimental data. © 2004 MAIK "Nauka/Interperiodica".
Quantum-chemical open-shell method with parametrization INDO is used to construct the model of a ... more Quantum-chemical open-shell method with parametrization INDO is used to construct the model of a large unit cell for the [Si-V ] 0 impurity complex in diamond. It is shown that the ground spin-triplet state of the complex exerts tunnel (rather than Jahn-Teller) splitting associated with off-center shift of Si atom along the trigonal axis of the fully symmetric atomic configuration D 3 d . Therefore, this complex, being a source of electron spin resonance KUL 1 S = 1, may appear to be the known optical 1.68-eV center with a typical ( ≈ 1 meV) splitting of the zero-phonon line. The intracenter optical excitation occurs from the filled orbital doublet localized at Si to the orbital doublet localized at three of six carbon atoms neighboring Si and has a multiplet structure.
The electron structures of two forms of the grafted carbon dimer for the (8, 0) zigzag nanotube w... more The electron structures of two forms of the grafted carbon dimer for the (8, 0) zigzag nanotube were calculated by the semi-empirical quantum-chemistry method applied to the supercell model. If the dimer adsorbs above the center of the tube's hexagon (h-grafting), it performs the topochemical transformation of the tube, according to the Stone–Wales scheme of inverse kind. B-grafting is a chemisorption above tube's bond, it is energetically lower, than h-grafting. Atomic structure of b-grafting is a splitted di-interstitial. Measuring the electronic density of states in the upper valence bandhas been shown to make it possible to distinguish between pure and grafted nanotubes, as well as between band h-graftings.
Semiconductors, 2003
[60]Fullerene solid films deposited by vacuum sublimation on polymer substrates were studied by m... more [60]Fullerene solid films deposited by vacuum sublimation on polymer substrates were studied by methods of X-ray 23 diffraction structure analysis, IR optical transmission, and laser-excited photoluminescence (PL) spectroscopy. Mechanism of 24 good chemical adsorption to centers with unsaturated bonds C=N and C≡N was on trial. Room-temperature PL band at 1.78 25 eV has its origin in interface chemical bonds or molecular complexes, that arise most probably according to Diels-Alder 26 cyclo-addition of fullerene and polymer molecules. 27
Physics of the Solid State, 2001
Earlier, we found the energies of formation and the electron band structures of the fullerene mol... more Earlier, we found the energies of formation and the electron band structures of the fullerene molecule C 60 and its methylated and hydrogenated chemical derivatives with saturated r 6 bonds of the type C 60 (CH 3 -r 6 -H) n with n from 1 to 6. Based on the self-consistent molecular-orbital method, we found the energies of singlet and triplet excitations for each molecule by the ∆ SCF technique. We compared the electron structure of the fullerene molecule with experimental data and other theoretical calculations and showed that the semiempirical quantum-chemical technique used in our work satisfactorily explains the experimental photoluminescence spectra of fullerene-containing star-shaped polystyrenes. Partial or complete removal of the dipole inhibition for the transitions in isomers that are formed upon chemical saturation of double bonds makes it possible to follow changes in the electron structure of the p π shell of the fullerene molecule by spectroscopic techniques. Specific optical spectra of the first excited singlet states (spectra of absorption, luminescence, and excitation of luminescence) as well as phosphorescence of the first spin-triplet state are described. © 2001 MAIK "Nauka/Interperiodica".
Microelectronic Engineering, 2003
The results of investigations of the structure and optical properties of films of fullerene C 60 ... more The results of investigations of the structure and optical properties of films of fullerene C 60 are reported. The films were obtained by vacuum thermal evaporation on substrates from heat-resistant polymers (polyacrylonitrile and cyclized polyacrylonitrile in composition with polyimide). The structure of C 60 films was determined by X-ray diffractometry. In all diffraction patterns of fullerene films, their structure manifests itself through reflections from the (111), (220), and (311) planes. Cubic C 60 films were obtained by fullerene deposition at substrate temperatures as high as 200 ° C. Atomic force microscopy of the film surface revealed the existence of a laminated structure. The infrared (IR) transmission spectra are indicative of the presence and constancy of the position of characteristic bands of C 60 (527, 576, 1183, and 1428 cm -1 ) for all fullerene films. The investigation of photoluminescence of fullerene films revealed bands whose energy position both exceeded typical values for molecular C 60 or fell below these values. This circumstance is caused by the interaction between the electron π systems of C 60 and the polymer substrate at the heterointerface, as well as by the photopolymerization reaction of fullerene under the effect of high-energy laser radiation and by the emergence of trap centers in the films.
It is shown that, in Auger-electron spectra of three-dimensional semimetal graphite and two-dimen... more It is shown that, in Auger-electron spectra of three-dimensional semimetal graphite and two-dimensional graphite (a zero band-gap semiconductor), an energy gap should be observed between the thresholds (edges) of the forward and inverse processes (threshold gap). In the one-electron approximation, this gap is zero, since the threshold for the Auger spectrum of the forward process is the minimum hole energy in the valence band, while the threshold for the spectrum of the inverse process is the minimum energy of conduction electrons. Inclusion of the electron correlation at the Fermi surface within the quantum-chemical approximation of a single open electron shell for multiplet structures of the restricted Hartree-Fock method makes it possible to determine the threshold gap as 1.5 eV for a 48-atom cyclic model of three-dimensional graphite and as 2.0 eV for a 24-atom model of two-dimensional graphite. The threshold gap does not contain the Fermi energy, in contrast to the Auger spectrum thresholds, where (4.0 eV -ε F ) for the forward Auger spectrum (holes) and ( − 1.1 eV + ε F ) for the inverse spectrum (conduction electrons), the sum of which gives this gap. The results of calculations for the forward Auger spectra of three-dimensional graphite (including the conclusion that electron correlation of holes in the top valence bands is weak in the Auger process) are shown to agree with the experimental data. © 2004 MAIK "Nauka/Interperiodica".
Quantum-chemical open-shell method with parametrization INDO is used to construct the model of a ... more Quantum-chemical open-shell method with parametrization INDO is used to construct the model of a large unit cell for the [Si-V ] 0 impurity complex in diamond. It is shown that the ground spin-triplet state of the complex exerts tunnel (rather than Jahn-Teller) splitting associated with off-center shift of Si atom along the trigonal axis of the fully symmetric atomic configuration D 3 d . Therefore, this complex, being a source of electron spin resonance KUL 1 S = 1, may appear to be the known optical 1.68-eV center with a typical ( ≈ 1 meV) splitting of the zero-phonon line. The intracenter optical excitation occurs from the filled orbital doublet localized at Si to the orbital doublet localized at three of six carbon atoms neighboring Si and has a multiplet structure.