Vladimir Kuznetsov - Academia.edu (original) (raw)

Papers by Vladimir Kuznetsov

Research paper thumbnail of Topology and Electronic Structure of Onion-Like Carbon and Graphite/Diamond Nanocomposites

MRS Proceedings, 2001

ABSTRACTAnnealing of nanodiamond at moderate temperature makes it possible to produce structures ... more ABSTRACTAnnealing of nanodiamond at moderate temperature makes it possible to produce structures being intermediate in the carbon transformation from sp3- to sp2-state (graphite/diamond nanocomposites) and onion-like carbon (OLC). Electron microscopy shows such structures involve cage shells with spacing close to graphite. X-ray emission spectroscopy has been applied to examine the electronic structure of OLC and graphite/diamond nanocomposites. The CKα-spectra of OLC produced in the temperature range of 1600-1900 K were found to be markedly different from the spectrum of particles formed at 2140 K and characterized by better ordering of graphitic shells. The latter spectrum was shown to be very similar to the CKα-spectrum of polycrystalline graphite, while the former ones exhibited a significant increase of high-energy maximum that might be caused by the holed defect structure of graphitic networks forming at the intermediate annealing temperatures. To interpret experimental spectr...

Research paper thumbnail of Electron-Electron Interaction in Carbon Nanostructures

NATO Science Series, 2007

The electron-electron interaction in carbon nanostructures was studied. A new method which allows... more The electron-electron interaction in carbon nanostructures was studied. A new method which allows to determine the electron-electron interaction constant λ c from the analysis of quantum correction to the magnetic susceptibility and the magnetoresistance was developed. Three types of carbon materials: arc-produced multiwalled carbon nanotubes (arc-MWNTs), CVD-produced catalytic multiwalled carbon nanotubes (c-MWNTs) and pyrolytic carbon were used for investigation. We found that λ c =0.2 for arc-MWNTs (before and after bromination treatment); λ c = 0.1 for pyrolytic graphite; λ c > 0 for c-MWNTs. We conclude that the curvature of graphene layers in carbon nanostructures leads to the increase of the electron-electron interaction constant λ c .

Research paper thumbnail of Photoemission spectroscopy of clean and potassium-intercalated carbon onions

Physical Review B, 2003

Hollow onionlike carbon ͑OLC͒, generated by annealing nanodiamond at 2140 K, has been studied by ... more Hollow onionlike carbon ͑OLC͒, generated by annealing nanodiamond at 2140 K, has been studied by core-level and valence-band photoemission spectroscopy. Upon intercalation with potassium, core and valence states of the OLC show an almost rigid shift to higher binding energies, and the density of states at the Fermi level (E F) is observed to increase. An asymmetric broadening of the C1s line from the OLC as intercalation proceeds indicates an increase in electron-hole pair excitations. Both core and valence-band spectra are consistent with charge transfer from the intercalated potassium to the OLC, and support the conclusion that the electronic structure of the carbon onions bears strong similarity to that of graphite, although differences do exist. In consequence the conclusion can be drawn that these species behave as graphite ''nanocrystals'' rather than as large fullerene molecules.

Research paper thumbnail of Photoinduced transparency of a suspension of onion-like carbon nanoparticles

Technical Physics Letters, 2009

We have observed the phenomenon of photoinduced transparency in a suspension of onion-like carbon... more We have observed the phenomenon of photoinduced transparency in a suspension of onion-like carbon (OLC) nanoparticles in N,N-dimethylformamide (DMF) under the action of high-power laser radiation (λ = 1064 nm). The OLC particles were prepared from detonation nanodiamonds (NDs) by means of high-temperature annealing in vacuum and then ultrasonically dispersed in DMF. Upon exposure to laser radiation, the optical density of the suspension significantly decreases in the visible and near-infrared range, but increases in the range of wavelengths below 400 nm.

Research paper thumbnail of Comparative study of reflectance properties of nanodiamonds, onion-like carbon and multiwalled carbon nanotubes

physica status solidi (b), 2011

Research paper thumbnail of Detonation nanodiamond and onion-like carbon: applications in composites

physica status solidi (a), 2008

Research paper thumbnail of Potential of 129Xe NMR spectroscopy of adsorbed xenon for testing the chemical state of the surface of mesoporous carbon materials illustrated by the example of aggregates of diamond and onion-like carbon nanoparticles

Kinetics and Catalysis, 2009

The chemical shift in the 129 Xe NMR spectrum of adsorbed xenon is very sensitive to the presence... more The chemical shift in the 129 Xe NMR spectrum of adsorbed xenon is very sensitive to the presence of oxygen-containing functional groups on the surface of mesoporous carbon materials. Well-characterized, structurally similar nanodiamond and onion-like carbon samples are considered here as model objects.

Research paper thumbnail of Photoemission study of onionlike carbons produced by annealing nanodiamonds

Physical Review B, 2005

Photoelectron spectroscopy has been used to study the products resulting from high temperature ph... more Photoelectron spectroscopy has been used to study the products resulting from high temperature phase transformation of nanodiamonds ͑ND͒. Depending on the temperature of annealing various particles with a diamond core covered by nanometer sized fullerene-like shells, and onionlike carbon ͑OLC͒ were formed. Analysis of the C1s photoemission lines of the intermediates of ND transformation, prepared at temperatures of 1420 and 1600 K and then exposed to atmosphere, reveals the presence of oxygen-containing groups and both sp 2 and sp 3 carbon. The sp 2 component for these samples has binding energies of 284.70± 0.05 eV ͑for the sample prepared at 1420 K͒ and 284.50± 0.05 eV ͑for the sample prepared at 1600 K͒. A difference of 1.3± 0.1 eV in the binding energy of the sp 3 and sp 2 components was observed. The sp 2 component for OLC prepared at 1800, 1900, and 2140 K has a binding energy of 284.45± 0.05 eV. The shift towards higher binding energies of the sp 2 component of the samples prepared at lower temperatures is explained by significant curvature of graphite layers formed in the initial stages of graphitization. The observed increase in density of states at the Fermi level for the samples prepared at 1600, 1800, and 1900 K is associated with an accumulation of different types of defects in the curved graphite layers during graphitization of diamond. The Lorentzian widths of C1s photoemission lines from OLC are large compared with those of HOPG. The possible reasons for this broadening are discussed.

Research paper thumbnail of Comparison of the Level and Mechanisms of Toxicity of Carbon Nanotubes, Carbon Nanofibers, and Silicon Nanotubes in Bioassay with Four Marine Microalgae

Nanoparticles (NPs) have various applications in medicine, cosmetics, optics, catalysis, environm... more Nanoparticles (NPs) have various applications in medicine, cosmetics, optics, catalysis, environmental purification, and other areas nowadays. With an increasing annual production of NPs, the risks of their harmful influence to the environment and human health is rising. Currently, our knowledge about the mechanisms of interaction between NPs and living organisms is limited. Additionally, poor understanding of how physical and chemical characteristic and different conditions influence the toxicity of NPs restrict our attempts to develop the standards and regulations which might allow us to maintain the safe living conditions. The marine species and their habitat environment are under continuous stress due to anthropogenic activities which result in the appearance of NPs in the aquatic environment. Our study aimed to evaluate and compare biochemical effects caused by the influence of different types of carbon nanotubes, carbon nanofibers, and silica nanotubes on four marine microalga...

Research paper thumbnail of Direct vapor-phase bromination of multiwall carbon nanotubes

Journal of Nanotechnology, 2012

We present the simple procedure of the vapor-phase bromination of multiwall carbon nanotubes (MWN... more We present the simple procedure of the vapor-phase bromination of multiwall carbon nanotubes (MWNTs) at moderate temperatures. MWNTs with average diameter 9 ± 3 nm were treated with Br 2 vapors at 250 • C to produce Br-functionalized product. Transmission electron microscopy analysis was used to prove low damage of MWNT walls during bromination. X-ray photoelectron spectroscopy (XPS) and differential thermal analysis (DTA) were used to investigate chemical composition of the surface of initial and brominated nanotubes. The experimental results show that the structure of MWNTs is not affected by the bromination process and the total amount of Br-containing surface functions reaches 2.5 wt. %. Electrophysical properties of initial and brominated MWNTs were investigated showing decrease of conductivity for functionalized sample. Possible mechanism of the vapor-phase bromination via surface defects and oxygen-containing functional groups was proposed according to data obtained. Additional experiments with bromination of annealed low-defected MWNTs were performed giving Br content a low as 0.75 wt. % proving this hypothesis.

Research paper thumbnail of Structural and Physical Properties of MWNT/Polyolefine Composites

Fullerenes Nanotubes and Carbon Nanostructures, 2012

Composite materials containing multi-walled carbon nanotubes (MWNT) in polyolefine (polyethylene ... more Composite materials containing multi-walled carbon nanotubes (MWNT) in polyolefine (polyethylene and polypropylene) matrix were prepared by coagulation precipitation. The morphology and structure of produced composites was investigated by scanning and transmission electron microscopy. Thermal analysis (oxidation in air) was performed for composites in temperature range 20–500°C. It was shown that the addition of MWNT increases the thermal stability of composites.

Research paper thumbnail of Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD)

Science and technology …, Jan 1, 1995

Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD). Vladimir L Kuznetsov,... more Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD). Vladimir L Kuznetsov, Andrej L Chuvilin, Yurij V Butenko, Igor' Yu Mal'kov, Anton K Gutakovskij, Sergej V Stankus, Rashid A Khajrulin Science and technology of fullerene materials, 105-110, 1995. ...

Research paper thumbnail of Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

… status solidi (b), Jan 1, 2009

A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) compos... more A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) composite is shown to present high electromagnetic (EM) shielding. EM shielding effectiveness (SE) was investigated in the frequency range 26-37 GHz (Ka-band). It was found that SE of the given composites strongly depends on MWCNT content. The highest EM attenuation reaching À37 dB at 28 GHz was observed for polymer film comprising 10 wt.% of MWCNT. Data on SE correlates well with the electrical conductivity measured by four-probe technique and by broadband dielectric spectroscopy (20 Hz-1 MHz). Both microwave and low-frequency analysis demonstrate low percolation threshold (lower than 1 wt.%) for the produced MWCNT/PMMA composites. At the same time significant electromagnetic interference absorbance demonstrates the contribution of the absorbance mechanisms specific for carbon nanostructures different of the main conductance mechanism.

Research paper thumbnail of Heterogeneous electronic states in carbon nanostructures with different dimensionalities and curvatures of the constituent graphene layers

Physics-Uspekhi, Jan 1, 2005

Page 1. 8. Bykov AA et al. Pis'ma Zh. Eksp. Teor. Fiz. 74 182 (2001) [JETP Lett. 74 164 (200... more Page 1. 8. Bykov AA et al. Pis'ma Zh. Eksp. Teor. Fiz. 74 182 (2001) [JETP Lett. 74 164 (2001)] 9. Entin MV, Magarill LI Phys. Rev. B 64 085330 (2001) 10. Entin MV, Magarill LI Phys. Rev. B 66 205308 (2002) 11. Magarill LI, EÂ ntin MV Zh. Eksp. Teor. Fiz. ...

Research paper thumbnail of Controllable electromagnetic response of onion‐like carbon based materials

… status solidi (b), Jan 1, 2008

The user has requested enhancement of the downloaded file.

Research paper thumbnail of Transformation of diamond nanoparticles into carbon onions under electron irradiation

Phys. Chem. Chem. …, Jan 1, 2002

Page 1. Transformation of diamond nanoparticles into carbon onions under electron irradiation VV ... more Page 1. Transformation of diamond nanoparticles into carbon onions under electron irradiation VV Roddatis,*y a VL Kuznetsov, b Yu. V. Butenko, b DS Su a and R. Schlögl a a Department of Inorganic Chemistry, Fritz Haber ...

Research paper thumbnail of Oxidative dehydrogenation of ethylbenzene to styrene over ultra-dispersed diamond and onion-like carbon

Carbon, Jan 1, 2007

30 8413 44 05 (D. Su), tel.: +33 3 9024 28 11; fax: +33 3 90 24 27 61 (N. Keller).

Research paper thumbnail of Evidence of an Equimolar C2H2–CO2 Reaction in the Synthesis of Carbon Nanotubes

Angewandte …, Jan 1, 2007

Research paper thumbnail of Thermodynamic analysis of nucleation of carbon deposits on metal particles and its implications for the growth of carbon nanotubes

Physical Review B, Jan 1, 2001

By considering the catalytic mechanisms underlying the formation of various nanocarbon deposits o... more By considering the catalytic mechanisms underlying the formation of various nanocarbon deposits on catalytic metal surfaces, we conclude that the majority of these mechanisms include some common steps. The most important of these is the nucleation of the carbon deposit on the metal surface. On the basis of experimental and literature data, we propose that the nucleus has the form of a flat saucer with its edges bonded to the metal surface. A thermodynamic analysis of the carbon nucleation on the metal surface is then performed to obtain an analytical equation for the dependence of the critical radius of the nucleus on the reaction parameters. This equation demonstrates that a variation of the reaction parameters, such as the temperature and the nature of the metal catalyst and promoters, can lead to the formation of different carbon deposits, such as filamentous carbon, multiwall nanotubes or single-wall nanotubes ͑SWNTs͒. The performed analysis allows us to conclude that SWNT growth is likely to proceed on liquid metal particles.

Research paper thumbnail of The Catalytic Use of Onion‐Like Carbon Materials for Styrene Synthesis by Oxidative Dehydrogenation of Ethylbenzene

Angewandte …, Jan 1, 2002

Research paper thumbnail of Topology and Electronic Structure of Onion-Like Carbon and Graphite/Diamond Nanocomposites

MRS Proceedings, 2001

ABSTRACTAnnealing of nanodiamond at moderate temperature makes it possible to produce structures ... more ABSTRACTAnnealing of nanodiamond at moderate temperature makes it possible to produce structures being intermediate in the carbon transformation from sp3- to sp2-state (graphite/diamond nanocomposites) and onion-like carbon (OLC). Electron microscopy shows such structures involve cage shells with spacing close to graphite. X-ray emission spectroscopy has been applied to examine the electronic structure of OLC and graphite/diamond nanocomposites. The CKα-spectra of OLC produced in the temperature range of 1600-1900 K were found to be markedly different from the spectrum of particles formed at 2140 K and characterized by better ordering of graphitic shells. The latter spectrum was shown to be very similar to the CKα-spectrum of polycrystalline graphite, while the former ones exhibited a significant increase of high-energy maximum that might be caused by the holed defect structure of graphitic networks forming at the intermediate annealing temperatures. To interpret experimental spectr...

Research paper thumbnail of Electron-Electron Interaction in Carbon Nanostructures

NATO Science Series, 2007

The electron-electron interaction in carbon nanostructures was studied. A new method which allows... more The electron-electron interaction in carbon nanostructures was studied. A new method which allows to determine the electron-electron interaction constant λ c from the analysis of quantum correction to the magnetic susceptibility and the magnetoresistance was developed. Three types of carbon materials: arc-produced multiwalled carbon nanotubes (arc-MWNTs), CVD-produced catalytic multiwalled carbon nanotubes (c-MWNTs) and pyrolytic carbon were used for investigation. We found that λ c =0.2 for arc-MWNTs (before and after bromination treatment); λ c = 0.1 for pyrolytic graphite; λ c > 0 for c-MWNTs. We conclude that the curvature of graphene layers in carbon nanostructures leads to the increase of the electron-electron interaction constant λ c .

Research paper thumbnail of Photoemission spectroscopy of clean and potassium-intercalated carbon onions

Physical Review B, 2003

Hollow onionlike carbon ͑OLC͒, generated by annealing nanodiamond at 2140 K, has been studied by ... more Hollow onionlike carbon ͑OLC͒, generated by annealing nanodiamond at 2140 K, has been studied by core-level and valence-band photoemission spectroscopy. Upon intercalation with potassium, core and valence states of the OLC show an almost rigid shift to higher binding energies, and the density of states at the Fermi level (E F) is observed to increase. An asymmetric broadening of the C1s line from the OLC as intercalation proceeds indicates an increase in electron-hole pair excitations. Both core and valence-band spectra are consistent with charge transfer from the intercalated potassium to the OLC, and support the conclusion that the electronic structure of the carbon onions bears strong similarity to that of graphite, although differences do exist. In consequence the conclusion can be drawn that these species behave as graphite ''nanocrystals'' rather than as large fullerene molecules.

Research paper thumbnail of Photoinduced transparency of a suspension of onion-like carbon nanoparticles

Technical Physics Letters, 2009

We have observed the phenomenon of photoinduced transparency in a suspension of onion-like carbon... more We have observed the phenomenon of photoinduced transparency in a suspension of onion-like carbon (OLC) nanoparticles in N,N-dimethylformamide (DMF) under the action of high-power laser radiation (λ = 1064 nm). The OLC particles were prepared from detonation nanodiamonds (NDs) by means of high-temperature annealing in vacuum and then ultrasonically dispersed in DMF. Upon exposure to laser radiation, the optical density of the suspension significantly decreases in the visible and near-infrared range, but increases in the range of wavelengths below 400 nm.

Research paper thumbnail of Comparative study of reflectance properties of nanodiamonds, onion-like carbon and multiwalled carbon nanotubes

physica status solidi (b), 2011

Research paper thumbnail of Detonation nanodiamond and onion-like carbon: applications in composites

physica status solidi (a), 2008

Research paper thumbnail of Potential of 129Xe NMR spectroscopy of adsorbed xenon for testing the chemical state of the surface of mesoporous carbon materials illustrated by the example of aggregates of diamond and onion-like carbon nanoparticles

Kinetics and Catalysis, 2009

The chemical shift in the 129 Xe NMR spectrum of adsorbed xenon is very sensitive to the presence... more The chemical shift in the 129 Xe NMR spectrum of adsorbed xenon is very sensitive to the presence of oxygen-containing functional groups on the surface of mesoporous carbon materials. Well-characterized, structurally similar nanodiamond and onion-like carbon samples are considered here as model objects.

Research paper thumbnail of Photoemission study of onionlike carbons produced by annealing nanodiamonds

Physical Review B, 2005

Photoelectron spectroscopy has been used to study the products resulting from high temperature ph... more Photoelectron spectroscopy has been used to study the products resulting from high temperature phase transformation of nanodiamonds ͑ND͒. Depending on the temperature of annealing various particles with a diamond core covered by nanometer sized fullerene-like shells, and onionlike carbon ͑OLC͒ were formed. Analysis of the C1s photoemission lines of the intermediates of ND transformation, prepared at temperatures of 1420 and 1600 K and then exposed to atmosphere, reveals the presence of oxygen-containing groups and both sp 2 and sp 3 carbon. The sp 2 component for these samples has binding energies of 284.70± 0.05 eV ͑for the sample prepared at 1420 K͒ and 284.50± 0.05 eV ͑for the sample prepared at 1600 K͒. A difference of 1.3± 0.1 eV in the binding energy of the sp 3 and sp 2 components was observed. The sp 2 component for OLC prepared at 1800, 1900, and 2140 K has a binding energy of 284.45± 0.05 eV. The shift towards higher binding energies of the sp 2 component of the samples prepared at lower temperatures is explained by significant curvature of graphite layers formed in the initial stages of graphitization. The observed increase in density of states at the Fermi level for the samples prepared at 1600, 1800, and 1900 K is associated with an accumulation of different types of defects in the curved graphite layers during graphitization of diamond. The Lorentzian widths of C1s photoemission lines from OLC are large compared with those of HOPG. The possible reasons for this broadening are discussed.

Research paper thumbnail of Comparison of the Level and Mechanisms of Toxicity of Carbon Nanotubes, Carbon Nanofibers, and Silicon Nanotubes in Bioassay with Four Marine Microalgae

Nanoparticles (NPs) have various applications in medicine, cosmetics, optics, catalysis, environm... more Nanoparticles (NPs) have various applications in medicine, cosmetics, optics, catalysis, environmental purification, and other areas nowadays. With an increasing annual production of NPs, the risks of their harmful influence to the environment and human health is rising. Currently, our knowledge about the mechanisms of interaction between NPs and living organisms is limited. Additionally, poor understanding of how physical and chemical characteristic and different conditions influence the toxicity of NPs restrict our attempts to develop the standards and regulations which might allow us to maintain the safe living conditions. The marine species and their habitat environment are under continuous stress due to anthropogenic activities which result in the appearance of NPs in the aquatic environment. Our study aimed to evaluate and compare biochemical effects caused by the influence of different types of carbon nanotubes, carbon nanofibers, and silica nanotubes on four marine microalga...

Research paper thumbnail of Direct vapor-phase bromination of multiwall carbon nanotubes

Journal of Nanotechnology, 2012

We present the simple procedure of the vapor-phase bromination of multiwall carbon nanotubes (MWN... more We present the simple procedure of the vapor-phase bromination of multiwall carbon nanotubes (MWNTs) at moderate temperatures. MWNTs with average diameter 9 ± 3 nm were treated with Br 2 vapors at 250 • C to produce Br-functionalized product. Transmission electron microscopy analysis was used to prove low damage of MWNT walls during bromination. X-ray photoelectron spectroscopy (XPS) and differential thermal analysis (DTA) were used to investigate chemical composition of the surface of initial and brominated nanotubes. The experimental results show that the structure of MWNTs is not affected by the bromination process and the total amount of Br-containing surface functions reaches 2.5 wt. %. Electrophysical properties of initial and brominated MWNTs were investigated showing decrease of conductivity for functionalized sample. Possible mechanism of the vapor-phase bromination via surface defects and oxygen-containing functional groups was proposed according to data obtained. Additional experiments with bromination of annealed low-defected MWNTs were performed giving Br content a low as 0.75 wt. % proving this hypothesis.

Research paper thumbnail of Structural and Physical Properties of MWNT/Polyolefine Composites

Fullerenes Nanotubes and Carbon Nanostructures, 2012

Composite materials containing multi-walled carbon nanotubes (MWNT) in polyolefine (polyethylene ... more Composite materials containing multi-walled carbon nanotubes (MWNT) in polyolefine (polyethylene and polypropylene) matrix were prepared by coagulation precipitation. The morphology and structure of produced composites was investigated by scanning and transmission electron microscopy. Thermal analysis (oxidation in air) was performed for composites in temperature range 20–500°C. It was shown that the addition of MWNT increases the thermal stability of composites.

Research paper thumbnail of Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD)

Science and technology …, Jan 1, 1995

Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD). Vladimir L Kuznetsov,... more Study of onion-like carbon(OLC) formation from ultra disperse diamond(UDD). Vladimir L Kuznetsov, Andrej L Chuvilin, Yurij V Butenko, Igor' Yu Mal'kov, Anton K Gutakovskij, Sergej V Stankus, Rashid A Khajrulin Science and technology of fullerene materials, 105-110, 1995. ...

Research paper thumbnail of Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

… status solidi (b), Jan 1, 2009

A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) compos... more A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) composite is shown to present high electromagnetic (EM) shielding. EM shielding effectiveness (SE) was investigated in the frequency range 26-37 GHz (Ka-band). It was found that SE of the given composites strongly depends on MWCNT content. The highest EM attenuation reaching À37 dB at 28 GHz was observed for polymer film comprising 10 wt.% of MWCNT. Data on SE correlates well with the electrical conductivity measured by four-probe technique and by broadband dielectric spectroscopy (20 Hz-1 MHz). Both microwave and low-frequency analysis demonstrate low percolation threshold (lower than 1 wt.%) for the produced MWCNT/PMMA composites. At the same time significant electromagnetic interference absorbance demonstrates the contribution of the absorbance mechanisms specific for carbon nanostructures different of the main conductance mechanism.

Research paper thumbnail of Heterogeneous electronic states in carbon nanostructures with different dimensionalities and curvatures of the constituent graphene layers

Physics-Uspekhi, Jan 1, 2005

Page 1. 8. Bykov AA et al. Pis'ma Zh. Eksp. Teor. Fiz. 74 182 (2001) [JETP Lett. 74 164 (200... more Page 1. 8. Bykov AA et al. Pis'ma Zh. Eksp. Teor. Fiz. 74 182 (2001) [JETP Lett. 74 164 (2001)] 9. Entin MV, Magarill LI Phys. Rev. B 64 085330 (2001) 10. Entin MV, Magarill LI Phys. Rev. B 66 205308 (2002) 11. Magarill LI, EÂ ntin MV Zh. Eksp. Teor. Fiz. ...

Research paper thumbnail of Controllable electromagnetic response of onion‐like carbon based materials

… status solidi (b), Jan 1, 2008

The user has requested enhancement of the downloaded file.

Research paper thumbnail of Transformation of diamond nanoparticles into carbon onions under electron irradiation

Phys. Chem. Chem. …, Jan 1, 2002

Page 1. Transformation of diamond nanoparticles into carbon onions under electron irradiation VV ... more Page 1. Transformation of diamond nanoparticles into carbon onions under electron irradiation VV Roddatis,*y a VL Kuznetsov, b Yu. V. Butenko, b DS Su a and R. Schlögl a a Department of Inorganic Chemistry, Fritz Haber ...

Research paper thumbnail of Oxidative dehydrogenation of ethylbenzene to styrene over ultra-dispersed diamond and onion-like carbon

Carbon, Jan 1, 2007

30 8413 44 05 (D. Su), tel.: +33 3 9024 28 11; fax: +33 3 90 24 27 61 (N. Keller).

Research paper thumbnail of Evidence of an Equimolar C2H2–CO2 Reaction in the Synthesis of Carbon Nanotubes

Angewandte …, Jan 1, 2007

Research paper thumbnail of Thermodynamic analysis of nucleation of carbon deposits on metal particles and its implications for the growth of carbon nanotubes

Physical Review B, Jan 1, 2001

By considering the catalytic mechanisms underlying the formation of various nanocarbon deposits o... more By considering the catalytic mechanisms underlying the formation of various nanocarbon deposits on catalytic metal surfaces, we conclude that the majority of these mechanisms include some common steps. The most important of these is the nucleation of the carbon deposit on the metal surface. On the basis of experimental and literature data, we propose that the nucleus has the form of a flat saucer with its edges bonded to the metal surface. A thermodynamic analysis of the carbon nucleation on the metal surface is then performed to obtain an analytical equation for the dependence of the critical radius of the nucleus on the reaction parameters. This equation demonstrates that a variation of the reaction parameters, such as the temperature and the nature of the metal catalyst and promoters, can lead to the formation of different carbon deposits, such as filamentous carbon, multiwall nanotubes or single-wall nanotubes ͑SWNTs͒. The performed analysis allows us to conclude that SWNT growth is likely to proceed on liquid metal particles.

Research paper thumbnail of The Catalytic Use of Onion‐Like Carbon Materials for Styrene Synthesis by Oxidative Dehydrogenation of Ethylbenzene

Angewandte …, Jan 1, 2002