Using the AFM tip, nanotubes are caught on a raw sample then deposited on a clean surface with an absolute precision better than 500nm. A nanostructured surface made of smooth Germanium dots on flat silicon was used as deposition sample. Nanotube mechanics is probed by AFM tip induced displacement. Nanotubes are shown to be blocked by Ge dots: it is impossible to induce a controlled displacement of the nanotube over a Ge dot when it is pushed against the dot. Elastic energy due to the bending of the nanotube is at the root of that behavior.

Carbon nanotubes were synthesized using several mesoporous silica templates with different pore sizes in order to investigate the possibility of controlling the diameter of carbon nanotubes by changing the pore size of the mesoporous silica. TEM observation confirmed that carbon nanotubes with uniform diameter can be obtained by the present method. However, it was found that it is difficult to prepare carbon nanotubes having diameter smaller than ∼20 nm by the present method even if the template with small pore size is used.

The transformation of an active carbon film with Pt nanoparticles to onion-like fullerenes has been in-situ investigated by a high-resolution transmission electron microscope. It was found that the onion-like fullerenes/metals polycrystalline film was formed under electron irradiation. The formation process was consisted of three steps: first, the flakes of onion-like fullerenes were induced by Pt nanoparticles; second, the flakes grew into a few ellipsoidal graphite shell; and third, a gradual reorganization of the formation of quasi-spheroid graphite shells and the bond of Pt particles was took place. It was a composite film of onion-like fullerenes and metal particles. It is suggested that the transformation mechanism involves an irradiation of electron and a catalytic effect of Pt nanoparticles, while any temperature rise due to electron irradiation seems to be negligibly small.

A novel mechanism of SWNT nucleation is considered in oppose to an existing model. The latter model based on the formation of a hemispherical carbon bowl nucleus has no correct description within the thermodynamics and kinetics of the nucleation process. The new mechanism can explain the prevalent formation of [10,10] armchair nanotube on the base of the continuum graphene energetics.

Here, we report successful measurements by surface Brillouin scattering (SBS) and scanning acoustic microscopy (SAM) of the elastic properties of small specimens of amorphous carbon obtained from C60 under high pressure and temperature. The superhard phases of amorphous carbon were synthesized from C60 at pressure 13 – 13.5 GPa and temperature 800–900°C. Two types of acoustic waves have been detected by SBS in superhard samples: surface Rayleigh wave and bulk longitudinal wave. The longitudinal velocity (νL) in the hardest sample is slightly lower than longitudinal wave velocity in diamond in [110] direction. Simultaneous measurements of the Rayleigh and longitudinal wave velocities make it possible to determine shear and bulk elastic moduli of the specimens. Obtained elastic properties for amorphous carbon synthesized under pressure 13.5 GPa and temperature 900°C are close to those for diamond, indicating that bonds among amorphous carbon network are diamond bonding dominated.

Nanofabrication on a hydrogen-terminated diamond surface is performed usingan atomic force microscope (AFM) anodization. Locally insulated areas less than 30 nm aresuccessfully obtained. Side-gated field effect transistors (FETs) are fabricated using the local anodization, and they operate successfully. Single hole transistors composed ofone side-gated FET and two tunneling junctions are also fabricated and operate at liquid nitrogen temperature (77 K).

In this work, the results of a study of the lithium insertion process in nanoporous carbons (NPC) obtained from carbides (SiC, TiC, Mo2C) by chlorination are presented. Lithium insertion was produced in the temperature range of 30–200 °C via the vacuum deposition and diffusion. The major analytical tools for study included nuclear reaction method and X-ray diffraction. Diffusion coefficients of lithium at this temperature interval were estimated. Possible mechanism of lithium diffusion is discussed. Investigation of phase composition of lithiated samples was carried out at room temperature. Phase composition is found to be dependent on the relationship between deposition and diffusion rates.

We report structural studies of large-scale wurtzite GaN nanowires fabricated by direct reaction of Ga vapor and NH3. This recently reported growth technique [1] demonstrates processing of GaN one-dimensional structures as thin as 26 nm and up to 500 μm in length. This method is both interesting and attractive in that fabrication is carried out without the assistance of template materials as required by other methods. In this study, transmission electron microscopy (TEM) is used to characterize the nanowires, while x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS) data provide supporting structural/compositional analysis. Our structural investigation reveals the presence of thin hexagonal platelets, which we believe play a critical role in the nucleation, growth, and orientation of the wires. In particular, our findings indicate that most of the wires grow along the [2110] direction, normal to the platelet edges.

In this paper, we have studied medium-range order structures in amorphous diamond-like carbon films with fluctuation microscopy. Medium-range order structures are quantified by a specific form of a general four-body correlation. We name this function as a pair-pair alignment correlation function. By analyzing speckle dark-field images taken over different areas as a function of momentum transfer in reciprocal space, we measured the pair-pair alignment correlation function for both thermally annealed samples and unannealed samples. We have found that thermal annealing introduces medium-range order in amorphous diamond-like carbon films, causing more pairs of atoms to be aligned. These results agree with density-functional simulations. Larger-scale simulations will be needed to fully understand our experimental results.

We present simulations of field emission from carbon nanotubes, using a transfer-matrix methodology. By repeating periodically a basic unit of the nanotubes in the region preceding that containing the extraction field, specific band-structure effects are included in the distribution of incident states, i.e. those entering the field region. The structures considered are the metallic (5,5) and the semiconducting (10,0) single-wall carbon nanotubes. The total-energy distributions of incident states show the gap of the (10,0) and the expected flat region for the (5,5) nanotube. The field-emitted electron energy distributions contain peaks, which are sharper for the (10,0) structure. Except for peaks associated with van Hove singularities in the distribution of incident states or with the Fermi level in the case of a metallic structure, all peaks are shifted to lower energies by the electric field.

The field emission properties of nanostructured carbon films deposited by cathodic vacuum arc in a He atmosphere have been studied by measuring the emission currents and the emission site density. The films have an onset field of ∼3 V/μm. The emission site density is viewed on a phosphor anode and it increases rapidly with applied field. It is assumed that the emission occurs from surface regions with a range of field enhancement factors but with a constant work function. The field enhancement factor is found to have an exponential distribution.

We have tried to prepare amorphous carbon oxynitrides (a-CNxOy)films by the oxygen radical treatment (ORT) of amorphous carbon nitrides (a-CNx) and also by the layer-by-layer method. Properties of a-CNxOy films were studied with X-ray photoelectron spectroscopy (XPS), photothermal deflection spectroscopy (PDS), ultraviolet-visible (UV-VIS) optical transmittance spectra, Raman spectra and electron spin resonance (ESR). Oxygen radical affects to a-CNx by etching, termination of defects and oxidation. A-CNxOy films are interesting for the application to luminescent materials and also to low dielectric consta nt materials.

Reported here is a study on the effect of different metal back contacts onthe electrical and structural properties of the tetrahedral amorphous carbon (ta-C). The films were grown using a pulsed cathodic arc system. Ta-C films were deposited simultaneously on silicon substrate, precoated with the following metals, namely aluminium (Al), gold (Au), chromium(Cr), molybdenum (Mo), copper (Cu), tungsten (W) and titanium(Ti). The electrical measurements and Raman response show that the back contact does influence the properties of ta-C films. These results are analysed with respect to our earlier report regarding the influence of back contacts on field emission from similar ta-C films.

Grazing incidence x-ray reflectivity has been employed to investigate ultra-thin films of tetrahedral amorphous carbon (ta-C) grown with an S-bend filtered cathodic vacuum arc. The results indicate that x-ray reflectivity can be used as a metrological tool for thickness measurements on films as thin as 0.5 nm, which is lower than the range required for carbon overcoats for magnetic hard disks and sliders if they are to reach storage densities of 100 Gbits/in2. The density of the films was derived from the best-fit to simulated reflectivity profiles from models for the structural parameters. In such thin films, the x-rays are reflected mainly at the film substrate interface, rather than the outer surface, so that the film density is derived from analysisof the oscillations of the post-critical angle reflectivity.

We report the electronic and structural properties of silicon doped carbon nanotubes using first principles calculations based on the density-functional theory. In the doped metallic nanotube a resonant state appears about 0.7 eV above the Fermi level and for the semiconductor tube the Si introduces an empty level at approximately 0.6 eV above the top of the valence band.

Near the temperature of 260 K, C60 crystal is known to undergo a first order phase transition, associated with changes in molecular rotations. The present paper reports the effect of the crystalline structure and impurity content of C60 thin films on their structural behavior near this phase transition. Polycrystalline C60 films with different grain sizes and oxygen content were obtained by varying the conditions of their vacuum deposition and post-grown exposure. Temperature-resolved X-ray diffraction in the range 300 – 15 K was used to determine the lattice parameter and its changes near the phase transition temperature. Decrease in grain sizes and increase in oxygen content of the films are found to lead to a gradual reduction in the discontinuity in lattice parameter and the transition temperature.

The electron field emission properties of sulfur-assisted nanocrystalline carbon (n-C: S) thin films grown on molybdenum substrates by hot-filament CVD technique using methane-hydrogen (CH4/H2) and hydrogen sulfide-hydrogen (H2S/H2) gas mixtures were investigated. The field emission properties of the S-assisted films are reported as a function of sulfur concentration. The incorporation of S caused structural and microstructural changes that were characterized with SEM, AFM and Raman spectroscopy (RS). The S-assisted films show smoother surfaces and smaller grains than those grown without. The lowest turn-on field measured was around 4.5 – 5.0 V/μm films grown with 500 ppm of hydrogen sulfide and at 900 °C. The electron field emission properties of S-assisted films were also compared to those grown without sulfur (i.e., intrinsic). An inverse correlation between the threshold field (Ec) and sulfur concentration was found. These finding are attributed to defect induced states within the electronic band structure.

As [60]fullerene is a very hydrophobic macromolecule, there have been a number of attempts to make it more hydrophilic for biomedical applications. By attaching hydrophilic moieties such as poly(oxyethylene)(POE) chains and cyclodextrin molecules to [60]fullerene, novel water-soluble and biocompatible materials have been successfully prepared [1,2].

The synthesis of novel macrocyclic fullerene conjugates which are water-soluble is reported. The telechelic fullerene derivatives have been prepared via addition reaction of POE-based arms with covalently bonded β-cyclodextrin (CD) to [60]fullerene. To this end, a mono-tosylated CD derivative has been prepared in pyridine and then reacted with an amino-functional POE in the presence of triethylamine. The subsequent reaction of [60]fullerene with the hydrophilic POE-conjugated CD-derivative yielded the macrofullerene after separation and purification procedures.

The macrocyclic [60]fullerene derivatives obtained were soluble in water and characterized by UV-VIS and FT-IR spectroscopy as well as light scattering measurements and thermogravimetric analysis.

Nanocrystalline diamonds with several hundred nm in diameter have been prepared in a 13.56 MHz low pressure inductively coupled CH4/H2 or CH4/CO/H2 plasma. The bonding structures were investigated by Raman spectroscopy and electron energy loss spectroscopy (EELS). Visible (514 nm) and UV (325, 244 nm) excited Raman spectra with CO additive exhibit peaks at ∼1150 cm-1 assigned to sp3 bonding and at 1332 cm-1 due to zone center optical phonon mode of diamond, respectively. It indicates that the UV excitations are possibly sufficient to excite the σ state of both sp2- and sp3-bonded carbon. The high resolution EELS (HREELS) spectra with CO additive show peaks at ∼1100 cm-1 assigned to C-C stretching vibration of sp3 bonding and at ∼700 cm corresponding to the bending vibration of sp3 bonding. It is qualitatively agreement with the Raman spectra. Furthermore the EELS spectrum without CO additive exhibits two peaks at 284 eV and at 292 eV corresponding to π* states and σ* states, respectively, and is similar to that of graphite rather than that of sp2-rich amorphous carbon. The EELS spectrum with CO additive, on the other hand, shows a peak at 292 eV due to σ * states and is similar to that of diamond. A slight peak appears at ∼285 eV corresponding to π* states. It consequently implies that the particles almost consist of sp3 bondings and that the small amount of sp2 bondings are considered to exist in grain boundaries. The EESL spectra are consistent with the results of Raman scattering and HREELS.

Interactions of metal atoms (Al, Ti) with semiconducting single walled carbon nanotube (SWNT) are investigated using first-principles pseudopotential calculations. Six different adsorption configurations for aluminum and titanium atoms are studied. Comparison of the energetics of these metal atoms on (8,0) SWNT surface shows significant differences in binding energy and diffusion barrier. These differences give an insight to explain why most of metal atoms (such as Al) form discrete particles on nanotube while continuous nanowires are obtained by using titanium in the experiment.