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1.
Y-branching of single walled carbon nanotubes 总被引:1,自引:0,他引:1
P. Nagy R. Ehlich L.P. Biró J. Gyulai 《Applied Physics A: Materials Science & Processing》2000,70(4):481-483
Y-branching was observed by scanning tunnelling microscopy (STM) in single wall carbon nanotubes grown by thermal decomposition
of C60 fullerene in the presence of transition metals. These novel carbon nanostructures may play an important role in carbon-based
nanoelectronics.
Received: 18 November 1999 / Accepted: 20 January 2000 / Published online: 8 March 2000 相似文献
2.
Thorn-like BN nanostructures that the nanosize hexagonal BN (h-BN) layers are randomly stacked looking like thorns were synthesized using thermal chemical vapor deposition of B/B2O3 under the flow of NH3 at 1200 °C. They can grow self-assembled forming the microsize lumps, and also deposit as sheathing layers on the pre-grown SiC nanowires with a controlled thickness in the range 20-100 nm. The spreading of the thorn-like BN layers as the sheathing layers results in a significantly enhanced surface area, 2400 m2/g. 相似文献
3.
Z. Wang F. Zhu W. Wang G. Yu M. Ruan 《Applied Physics A: Materials Science & Processing》2000,71(3):353-355
We report the observation of a carbon nanostructure grown on a graphite surface by Ar+ ion bombardment. We demonstrate experimentally that, in view of transmission electron microscopy (TEM)-based evidence, some
of these carbon nanostructures emerged the whiskerlike protrusion and/or the sputtered-surface, suggesting a new growth model
for nanocarbon, distinctly different from that found in arc-discharge and many other methods.
Received: 14 April 2000 / Accepted: 17 April 2000 / Published online: 13 July 2000 相似文献
4.
Honeycomb-like alignments of carbon nanotubes were prepared by pyrolysis of a metal phthalocyanine at 950 °C in an Ar/H2 flow. A simple synthetic method has been developed for a large-scale synthesis of aligned carbon nanotubes normal to a substrate
surface.
Received: 15 June 2000 / Accepted: 21 June 2000 / Published online: 2 August 2000 相似文献
5.
Scanning tunneling microscopy of carbon nanotubes 总被引:1,自引:0,他引:1
W. Clauss 《Applied Physics A: Materials Science & Processing》1999,69(3):275-281
This article reports on the application of scanning tunneling microscopy for the study of surface structures and electronic
properties of carbon nanotubes. Geometric effects resulting from the cylindrical shape of the tubes as well as the particular
band structure of the graphitic crystal lattice can lead to a variety of contrast patterns. On the atomic scale, it is sometimes
possible to see the full honeycomb lattice structure but often different structures are observed. Besides distortions caused
by tip–sample interactions, we find that a complex superstructure superimposed on the simple atomic contrast pattern arises
from elastic scattering of the Fermi states at defects or impurities. From a careful analysis of high-resolution images it
is possible to extract information about elastic strain of individual tubes. A new combination of scanning tunneling and scanning
force microscopy enables near-atomic point resolution of the force signal the tubes can be identified without the need of
a conducting substrate. This imaging mode is a crucial step for the characterization of electronic devices based on individual
single-wall tubes. This mode can be further enhanced by the use of single-walled tubes as probe tips.
Received: 17 May 1999 / Accepted: 18 May 1999 / Published online: 4 August 1999 相似文献
6.
G.S. Duesberg J. Muster H.J. Byrne S. Roth M. Burghard 《Applied Physics A: Materials Science & Processing》1999,69(3):269-274
Production methods for carbon nanotubes are now well established and allow their synthesis on a scale of grams per day. For
many potential applications of this unique material, its purification still remains a crucial problem. In this article various
purification methods for single- and multi-wall carbon nanotubes are reviewed. These methods are compared in terms of their
capacity, efficiency, and effects on the tubes. In addition, the use of Raman spectroscopy for monitoring the chromatographic
purification of single-wall nanotubes is described.
Received: 17 May 1999 / Accepted: 18 May 1999 / Published online: 29 July 1999 相似文献
7.
Filling carbon nanotubes 总被引:12,自引:0,他引:12
D. Ugarte T. Stöckli J.M. Bonard A. Châtelain W.A. de Heer 《Applied Physics A: Materials Science & Processing》1998,67(1):101-105
Received: 2 March 1998 相似文献
8.
Mechanical properties of carbon nanotubes 总被引:26,自引:0,他引:26
J.-P. Salvetat J.-M. Bonard N.H. Thomson A.J. Kulik L. Forró W. Benoit L. Zuppiroli 《Applied Physics A: Materials Science & Processing》1999,69(3):255-260
A variety of outstanding experimental results on the elucidation of the elastic properties of carbon nanotubes are fast appearing.
These are based mainly on the techniques of high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy
(AFM) to determine the Young’s moduli of single-wall nanotube bundles and multi-walled nanotubes, prepared by a number of
methods. These results are confirming the theoretical predictions that carbon nanotubes have high strength plus extraordinary
flexibility and resilience. As well as summarising the most notable achievements of theory and experiment in the last few
years, this paper explains the properties of nanotubes in the wider context of materials science and highlights the contribution
of our research group in this rapidly expanding field. A deeper understanding of the relationship between the structural order
of the nanotubes and their mechanical properties will be necessary for the development of carbon-nanotube-based composites.
Our research to date illustrates a qualitative relationship between the Young’s modulus of a nanotube and the amount of disorder
in the atomic structure of the walls. Other exciting results indicate that composites will benefit from the exceptional mechanical
properties of carbon nanotubes, but that the major outstanding problem of load transfer efficiency must be overcome before
suitable engineering materials can be produced.
Received: 17 May 1999 / Accepted: 18 May 1999 / Published online: 29 July 1999 相似文献
9.
M. Holzinger A. Hirsch P. Bernier G.S. Duesberg M. Burghard 《Applied Physics A: Materials Science & Processing》2000,70(5):599-602
A new purification procedure is introduced, which uses the advantages of column chromatography and vacuum filtration. Potassium
polyacrylate is used as stationary phase. This method is based on the idea that the size of the existing cavities in the polymer
increases during a swelling process in distilled water. The cavities are big enough to entrap the nanoparticles, but allow
for a free movement of nanotubes and bundles.
Received: 6 March 2000 / Accepted: 7 March 2000 / Published online: 5 April 2000 相似文献
10.
P.D. Townsend R. Brooks D.E. Hole Z. Wu A. Turkler N. Can A. Suarez-Garcia J. Gonzalo 《Applied physics. B, Lasers and optics》2001,73(4):345-353
The presence of copper nanoparticles in alumina and silica modifies their luminescence, and the changes in spectra are influenced
by variations in the nanoparticle size distributions. Luminescence signals are sensitive to the total defect population. Thus
the luminescence not only reflects changes caused by thermal annealing, which can modify both intrinsic defects and the copper
nanoparticles, but also responds to the method of preparation of thin film layers. Copper nanoparticle influence on luminescence
is reported both for ion-implanted bulk silica and for copper in pulsed laser deposition within alumina. Luminescence thus
potentially offers a non-destructive monitor of the layer quality, reproducibility and growth conditions, as well as the state
and size of the copper nanoparticles.
Received: 29 June 2001 / Published online: 10 October 2001 相似文献
11.
J. Lefebvre R. Antonov A.T. Johnson 《Applied Physics A: Materials Science & Processing》1998,67(1):71-74
Received: 10 February 1998 相似文献
12.
Spectroscopic properties and STM images of carbon nanotubes 总被引:2,自引:0,他引:2
A. Rubio 《Applied Physics A: Materials Science & Processing》1999,68(3):275-282
Received: 23 November 1998 / Accepted: 22 December 1998 相似文献
13.
G.S. Duesberg J. Muster V. Krstic M. Burghard S. Roth 《Applied Physics A: Materials Science & Processing》1998,67(1):117-119
Received: 18 May 1998/Accepted: 22 May 1998 相似文献
14.
A.S. da Silva Sobrinho G. Czeremuszkin M. Latrèche M.R. Wertheimer 《Applied Physics A: Materials Science & Processing》1999,68(1):103-105
2 or more).
Received: 1 September 1998/Accepted: 6 October 1998 相似文献
15.
H. Kersten D. Rohde H. Steffen H. Deutsch R. Hippler G.H.P.M. Swinkels G.M.W. Kroesen 《Applied Physics A: Materials Science & Processing》2001,72(5):531-540
A summary is given of different methods for the determination of the energy influx and its influence on the thermal balance
and energetic conditions of substrate surfaces during plasma processing. The discussed mechanisms include heat radiation and
kinetic and potential energy of charged particles and sputtered neutrals. For a few examples such as magnetron sputtering
of a-C:H films, sputter deposition of aluminum on microparticles, and titanium deposition in a hollow-cathode arc evaporation
device the energetic balance of substrates during plasma processing is presented.
Received: 6 July 2000 / Accepted: 12 December 2000 / Published online: 3 April 2001 相似文献
16.
Z.-X. Wang J. Hu A.-G. Li M.-L. Ruan 《Applied Physics A: Materials Science & Processing》2001,73(4):463-465
When examined under a high-resolution transmission microscope (HRTEM), highly oriented pyrolitic graphite (HOPG), after ultrasound
treatment, is found to contain some bent graphitic sheets. These bent structures are ordered graphitic sheets, which have
specific bend angles that are a multiple of 30° (from 30° to 180°). We speculate that the creation and variation of bend angles
is a result of interplay between the conformation of sp3-like defects and the ultrasound wave impact.
Received 8 September 2000 / Accepted: 6 November 2000 / Published online: 23 May 2001 相似文献
17.
L. Barbadillo F.J. Gómez M.J. Hernández J. Piqueras 《Applied Physics A: Materials Science & Processing》1999,68(5):603-607
Electron cyclotron resonance plasma chemical vapor deposition with nitrogen, methane, and argon-diluted silane as precursors
has been used to prepare SiCN thin films. Optical emission from CN species in the plasma has been observed. Infrared measurements
show that most of the nitrogen is incorporated to the thin solid films in the form of Si-N, C=N and C≡N bonds suggesting a
basic structure of incomplete SiN tetrahedra with C=N and C≡N bridging bonds. The deposited films are nearly transparent in
the visible range with a weak absorption threshold between 2.2 and 3.5 eV.
Received: 3 April 1998 / Accepted: 5 January 1999 / Published online: 31 March 1999 相似文献
18.
C.D. Scott S. Arepalli P. Nikolaev R.E. Smalley 《Applied Physics A: Materials Science & Processing》2001,72(5):573-580
Mechanisms proposed in the literature are compared with a current scenario for the formation of single-wall carbon nanotubes
in the laser-ablation process that is based on our spectral emission and laser-induced fluorescence measurements. It is suggested
that the carbon which serves as feedstock for nanotube formation not only comes from the direct ablation of the target, but
also from carbon particles suspended in the reaction zone. Fullerenes formed in the reaction zone may be photo-dissociated
into C2 and other low molecular weight species, and also may serve as feedstock for nanotube growth. Confinement of the nanotubes
in the reaction zone within the laser beam allows the nanotubes to be ‘purified’ and annealed during the formation process
by laser heating.
Received: 2 November 2000 / Accepted: 3 November 2000 / Published online: 23 March 2001 相似文献
19.
2 has been used for smoothing of rough InAs, InP, and InSb surfaces, prepared by argon ion beam etching (IBE). The evolution
of the surface roughness and morphology has been studied by atomic force microscopy (AFM) as a function of the N2 RIBE process parameters (ion beam energy, ion beam angle of incidence, and ion dose). A drastic improvement of the surface
roughness has been observed for ion beam angles near normal incidence and larger than 70° with increasing ion doses. By using
this technique, the initial root-mean-square (rms) roughness of, e.g., InSb of about 40 nm could be decreased to about 1 nm.
Received: 20 March 1998/Accepted: 24 March 1998 相似文献
20.
K. Morgenstern E. Laegsgaard I. Stensgaard F. Besenbacher M. Böhringer W.-D. Schneider R. Berndt F. Mauri A. De Vita R. Car 《Applied Physics A: Materials Science & Processing》1999,69(5):559-569
We investigate atomic and molecular nanostructures on metal surfaces by variable low-temperature scanning tunnelling microscopy.
In combination with molecular dynamics calculations we achieve a detailed understanding of the stability of these structures.?Atomic
nanostructures in homoepitaxial metallic systems are thermodynamically only metastable. Two-dimensional islands on Ag(110)
decay above a threshold temperature of T
l=175 K. Caused by the anisotropy of the surface, distinct decay behaviours exist above and below a critical temperature of
T
c=220 K. Calculations based on effective medium potentials of the underlying rate limiting atomic processes allow us to identify
the one-dimensional decay below T
c as well as the two-dimensional decay above T
c.?In contrast to atoms, the intermolecular electrostatic interaction of polar molecules leads to thermodynamically stable
structures. On the reconstructed Au(111) surface, the pseudo-chiral 1-nitronaphthalin forms two-dimensional supermolecular
clusters consisting predominantly of ten molecules. Comparison of images with submolecular resolution to local density calculations
elucidates the thermodynamical stability as well as the internal structure of the decamers.
Received: 25 March 1999 / Accepted: 17 August 1999 / Published online: 6 October 1999 相似文献