共查询到20条相似文献,搜索用时 31 毫秒
1.
A. M. Lebedev L. P. Sukhanov M. Brzhezinskaya K. A. Menshikov N. Yu. Svechnikov R. G. Chumakov V. G. Stankevich 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2017,11(4):814-822
The current work is dedicated to investigation of the interaction between self-assembled polar molecules of fullerene fluoride C60F18 with the chemically active surface Ni(100) under radiation and heat treatments. X-ray photoelectron spectroscopy is used in combination with quantum-chemical simulation. For the first time, the transformation of an as-deposited dielectric continuous 2D thin film to a 3D island-type assembly with molecular ordering within the islands is shown to take place. The degree of coverage of the Ni surface by C60F18 islands (0.6–0.7) and their height (~6 nm) are estimated. Quantum-chemical simulation shows that the chemisorption energy of the C60F18 molecule on the Ni surface equals ~6.6 eV and fluorine atoms are located at a distance of 1.9 Å above the Ni surface. The results of the investigation provide an opportunity to create nanoscale ordered structures with local changes in the work function. 相似文献
2.
O. A. Yermolenko G. V. Kornich S. G. Buga 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(2):217-221
A molecular dynamics simulation of the low-energy interaction of C60 fullerenes and Cu1@C60, Cu6@C60, and Cu13@C60 endofullerenes with a Cu(100) surface was performed. The effects of a copper cluster encapsulated in a fullerene and of a fullerene’s translational motion and rotation energy on its penetration into a surface were investigated. It was shown that the presence of an encapsulated cluster has a positive effect on fullerene penetration into a surface with preservation of the fullerene’s structure. The optimal conditions for fullerene penetration into a copper crystal surface were determined. 相似文献
3.
Vasily Lavrentiev Jiri Vacik Hiroshi Naramoto Kazumasa Narumi 《Applied Physics A: Materials Science & Processing》2009,95(3):867-873
The structure transformation occurring in fullerene film under bombardment by 50 keV C60+ cluster ions is reported. The Raman spectra of the irradiated C60 films reveal a new peak rising at 1458 cm−1 with an increase in the ion fluence. This feature of the Raman spectra suggests linear polymerization of solid C60 induced by the cluster ion impacts. The aligned C60 polymeric chains composing about 5–10 fullerene molecules have been distinguished on the film surface after the high-fluence
irradiation using atomic force microscopy (AFM). The surface profiling analysis of the irradiated films has revealed pronounced
sputtering during the treatment. The obtained results indicate that the C60 polymerization occurs in a deep layer situated more than 40 nm below the film surface. The deep location of the C60 polymeric phase indirectly confirms the dominant role of shock waves in the detected C60 phase transformation. 相似文献
4.
A. O. Pozdnyakov B. M. Ginzburg T. A. Maricheva V. V. Kudryavtsev O. F. Pozdnyakov 《Physics of the Solid State》2004,46(7):1371-1375
Polyimide-fullerene composite thin coatings are investigated using thermal desorption mass spectrometry in the temperature range 20–800°C. It is found that, at temperatures below the temperature of decom-position of the polymer matrix, thermally stimulated desorption of fullerene molecules is limited by the diffusion of fullerene molecules in the matrix. The diffusion coefficients and activation energies of diffusion of C60 and C70 fullerene molecules are determined from the experimental data on thermally stimulated desorption in the framework of several approaches. It is revealed that the diffusion of C70 molecules in the polyimide matrix is more hindered than the diffusion of C60 molecules in the same matrix. 相似文献
5.
V. A. Demin V. D. Blank A. R. Karaeva B. A. Kulnitskiy V. Z. Mordkovich Yu. N. Parkhomenko I. A. Perezhogin M. Yu. Popov E. A. Skryleva S. A. Urvanov L. A. Chernozatonskii 《Journal of Experimental and Theoretical Physics》2016,123(6):985-990
A new fully carbon nanocomposite material is synthesized by the immersion of carbon nanotubes in a fullerene solution in carbon disulfide. The presence of a dense layer of fullerene molecules on the outer nanotube surface is demonstrated by TEM and XPS. Fullerenes are redistributed on the nanotube surface during a long-term action of an electron beam, which points to the existence of a molecular bond between a nanotube and fullerenes. Theoretical calculations show that the formation of a fullerene shell begins with the attachment of one C60 molecule to a defect on the nanotube surface. 相似文献
6.
I. V. Davydov 《Physics of the Solid State》2007,49(6):1201-1206
The effect of heating of the electronic subsystem on the thermal stability of C60 and C20 fullerenes and a (C20)2 cluster molecule is investigated theoretically. It is demonstrated that the excitation of electrons to upper energy levels in accordance with the Fermi-Dirac distribution function does not lead to a substantial change in the activation energy E a for decay of the C20 fullerene. The stability of the C60 fullerene and the (C20)2 cluster molecule likewise does not change radically. However, the inclusion of corrections associated with the finite sizes of the heat bath leads to the activation energy E a which is in better agreement with the calculated height of the potential barrier preventing the cluster decay. 相似文献
7.
It is shown that, contrary to all previously studied systems, heating to ~800 K in the C60? TaS2 monolayer-Ta(100) adsorption system leads to the complete removal of the deposited fullerene molecules. A model is proposed that explains the observed phenomenon by a very weak nonchemisorption interaction between the C60 molecules and the valence-saturated surface of tantalum disulfide that forms layered crystals with van der Waals interaction between layers. 相似文献
8.
L. M. Ramaniah M. Boero 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(3):369-374
We report the first-principles Car-Parrinello molecular dynamics study of the behaviour of a single transition metal Ta atom
on fullerene C60, at different temperatures, and for both neutral and charged clusters. We seek to characterise the
motion of the lone Ta metal atom on the C60 surface, contrasting its behaviour both with that of three Ta atoms, as well as with a single alkali metal atom on the cage
surface.
Our earlier simulations on C60Ta3 had revealed that the Ta atoms on the surface of
the fullerene are affected by a rather high mobility, and that the motion of these atoms is highly correlated due to Ta-atom-Ta-atom
attraction. Earlier, experimental studies of a single metal atom (K, Rb) on the surface of a C60 molecule had led to the
inference that at room temperature the metal atom skates freely over the surface, the first direct evidence for which was presented by us in earlier first principles molecular dynamical simulations. 相似文献
9.
A. Leyderman E. I. Radovanova S. S. Sarkisov V. S. Vikhnin 《Physics of the Solid State》2005,47(11):2186-2195
The vibrational spectra of 2-cyclooctylamino-5-nitropyridine (COANP) solutions and the evolution of the spectra upon changing over from the solutions to solid-phase COANP are investigated. The bands observed in the spectra are assigned to the corresponding vibrational modes. The nature of the interaction of COANP with C60 and C70 fullerenes is elucidated by analyzing the transmission spectra of these compounds. No interaction of the COANP compound with C60 and C70 fullerenes is revealed under the studied conditions. It is assumed that the physical nature of this phenomenon can be associated with the formation of liquid-crystal clusters consisting of fullerene molecules. 相似文献
10.
A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced
at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the
dimer structure. 相似文献
11.
A. N. Enyashin V. V. Ivanovskaya Yu. N. Makurin A. L. Ivanovskii 《Physics of the Solid State》2004,46(8):1569-1573
A comparative analysis of the stability factors and electronic structure of two possible crystalline forms of small fullerene C28 and endohedral fullerene Zn@C28 with diamond and lonsdaleite structures is performed using a cluster model. Atoms of elements that, when placed inside C28 cages, have no significant effect on the stability of free small-fullerene molecules are shown to be able to dramatically change the electronic properties and reactivity of the C28 skeleton and to be favorable for forming small-fullerene crystalline modifications, which are covalent crystals. In contrast, if the presence of foreign atoms inside C28 cages stabilizes the isolated nanoparticles, then molecular crystals (such as C60 fullerites) are formed due to weak van der Waals forces. 相似文献
12.
O. E. Kvyatkovskii M. G. Shelyapina B. F. Shchegolev L. S. Vorotilova I. B. Zakharova 《Physics of the Solid State》2002,44(3):585-587
This paper reports on ab initio cluster calculations of the equilibrium geometry, electronic structure, and vibrational properties of the C60, C60F24, C60Cl24, C60Br24 molecules. 相似文献
13.
Carbon-based nanoparticles (NPs) such as fullerenes and nanotubes have been extensively studied for drug delivery in recent years. The permeation process of fullerene and its derivative molecules through membrane is essential to the utilization of fullerene-based drug delivery system, but the mechanism and the dynamics of permeation through cell membrane are still unclear. In this study, coarse-grained molecular dynamics simulations were performed to investigate the permeation process of functionalized fullerene molecules (ca. 0.72 nm) through the membrane. Our results show that single functionalized fullerene molecule in such nanoscale could permeate the lipid membrane in micro-second time scale. Pristine C60 molecules prefer to aggregate into several small clusters while C60OH15 molecules could aggregate into one big cluster to permeate through the lipid membrane. After permeation of C60 or its derivatives into membrane, all C60 and C60OH15 molecules disaggregated and monodispersed in the lipid membrane. 相似文献
14.
E. A. Kyzyma M. O. Kuzmenko L. A. Bulavin V. I. Petrenko I. V. Mikheev M. A. Zabolotnyi M. Kubovcikova P. Kopcansky M. V. Korobov M. V. Avdeev V. L. Aksenov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2016,10(6):1125-1128
The C60 and C70 fullerene-cluster size distribution in aqueous solutions and a physiological medium is studied via dynamic light scattering. The initial aqueous solutions of fullerenes obtained via different methods are found to contain clusters with a characteristic size of about 100 nm. The additional aggregation of fullerenes is observed after their transfer into a physiological medium (0.9% NaCl) and is established to depend on the preparation method. The cluster-size distribution in a fullerene–pectic-acid mixture is found to vary in water and a physiological medium. The results reveal the need for additional studies of the structure and properties of C60 and C70 molecules, as well as their complexes with medicines, in a physiological medium for medical applications. 相似文献
15.
A. I. Oreshkin R. Z. Bakhtizin J. T. Sadowski T. Sakurai 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(7):883-885
The morphology and atomic structure of C60 fullerene films on the Bi(0001)/Si(111)?7 × 7 surface with different coverages have been studied by scanning tunneling microscopy and spectroscopy and low-energy electron microscopy in high vacuum. It is shown that the most favorable sites for nucleation of C60 islands are double steps and domain boundaries on the surface of epitaxial Bi film. 相似文献
16.
The quenching of the electronically excited states of various energy donors—Tb3+; 9,10-anthracene dibromide; and adamantanone—by C70 fullerene has been detected and analyzed. The quenching is characterized by anomalously high biomolecular quenching rate constants, which are obtained from the Stern-Volmer dependences of the energy-donor photoluminescence intensity on the concentration of the C70 molecules. It has been shown that the high efficiency of quenching by the C70 fullerene as compared to the C60 fullerene is due to the higher polarizability of the C70 molecule and large overlap integrals of the energy-donor photoluminescence spectra with the absorption spectrum of the C70 fullerene. 相似文献
17.
S. Duffe T. Irawan M. Bieletzki T. Richter B. Sieben C. Yin B. von Issendorff M. Moseler H. Hövel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(3):401-408
The low energy deposition of silver cluster cations with
561 (±5) atoms on a cold fullerene covered gold surface has
been studied both by scanning tunneling microscopy and molecular
dynamics simulation. The special properties of the
C60/Au(111) surface result in a noticeable fixation of the
clusters without a significant change of the cluster shape. Upon
heating to room temperature we observe a flattening or shrinking
of the cluster samples due to thermal activation. Similar changes were observed also for mass selected Ag clusters with other
sizes. For comparison
we also studied Ag islands of similar size, grown by low
temperature deposition of Ag atoms and subsequent annealing. A
completely different behavior is observed with much broader size
distributions and a qualitatively different response to
annealing. 相似文献
18.
A. O. Pozdnyakov B. M. Ginzburg T. A. Maricheva V. V. Kudryavtsev M. A. Yagovkina O. F. Pozdnyakov 《Physics of the Solid State》2005,47(12):2333-2340
Polymer-C60 fullerene composite coatings are studied using thermal desorption mass spectrometry. It is found that thermal desorption spectra of C60 fullerene molecules can exhibit several resolved peaks (at a specified heating rate) corresponding to thermal desorption states. The relative intensity of the thermal desorption peaks depends on the procedure used for preparing the composite coatings, in particular, on the time of sedimentation of the polymer-fullerene suspension. The occurrence of different stages in thermally stimulated desorption of C60 fullerene molecules is explained by the fact that the fullerene molecules can exist in several phase states characterized by different densities and degrees of ordering in the polymer matrix. 相似文献
19.
We have carried out experimental and theoretical
studies on electron scattering from the C3H6 isomers and
C3F6 molecules and we report on total, differential as well
as theoretical integral elastic cross-sections for these
molecules. Vibrational excitation functions are also presented for
the typical vibrational peaks in C3H6 and cyclo-C3H6
for the angle of 90○, impact energy range of 1–16 eV
and loss energies of 0.12 eV and 0.13 eV, respectively. In the
cross-sections, clear differences in peak positions and magnitudes
between the C3H6 isomers can be viewed as the isomer effect.
The same is observed between C3H6 and C3F6 in a clear
manifestation of the fluorination effect. The resemblance of the
π* shape resonance in the cross-sections, observed at about
2.2 eV for C3H6 and 3.5 eV for C3F6, to those in
C2H4 and C2F4 clearly points to the effect of the
double bond in the molecular structures for these molecules.
Theoretical analysis is performed to provide rationales for the
scattering dynamics. 相似文献
20.
The possible existence of complexes formed by the C60 fullerene or its derivatives with transition metals interacting with the carbon cage via η6−π type bonding is discussed. The derivatives C60
R
6 of the C60 fullerene (R = −, H, F, Cl, Br, CN) are analyzed using the density functional method within the Perdew-Burke-Ernzerhof approximation.
In these molecules, the R groups are attached to carbon atoms located in the α positions with respect to the common hexagon of the C60 fullerene. The structure and electron configuration of complexes formed by these molecules with Cr(C6H6), Cr(CO)3, MoC6H6, and Mo(CO)3 particles are modeled. The “dimer” systems C60R6-M-R
6C60 (M = Cr, Mo, R =-, H, F) are investigated in which two fullerene molecules interact via a transition-metal atom. It is found that the introduction
of six R groups in the α sites with respect to the common hexagon of C60 favors the formation of complexes of these derivatives of the C60 fullerene with the Cr(C6H6), Cr(CO), Mo(C6H6), and Mo(CO)3 particles in which η6-π type bonds arise between the metal and the atoms of the hexagon fringed with the R groups. It is also demonstrated that analogous complexes with a “bare” C60 fullerene are possible, but they are significantly less stable. The (C6H6) M-R
6C60
R
6-M (C6H6) complexes of particles M(C6H6) (M= Cr, Mo) and derivatives R
6C60
R
6 (R =-, H, F, Cl, Br) are studied. In the R
6C60
R
6 molecule, six R groups are located in the α sites with respect to the common hexagon of the C60 fullerene and six other groups fringe the opposite hexagon. The obtained results can be applied to planning synthesis of
new complexes that C60 fullerene derivatives can form with transition metals.
Original Russian Text ¢ E.G. Gal’pern, A.R. Sabirov, I.V. Stankevich, 2007, published in Fizika Tverdogo Tela, 2007, Vol.
49, No. 12, pp. 2220–2223. 相似文献