The use of Raman spectroscopy to reveal the remarkable structure and properties of carbon nanotubes is briefly reviewed. Particular emphasis is given to the fact that a nanotube can be semiconducting or metallic depending on its diameter dt and chirality θ , and how Raman spectroscopy at the single nanotube level reveals such information. Some of the implications of the unusual properties of ca...

The magnetic properties of iron nanoparticles partially encapsulated at the tips of aligned carbon nanotubes have been studied. The carbon nanotube wall not only protects the metallic particles from oxidization, but also reduces the inter-particle dipolar interaction by non-magnetic separation. Magnetic characterizations performed in the temperature range of 5–350K with magnetic field up to 3T ...

The current-degradation mechanism of a fully sealed, carbon-nanotube field emission display is investigated experimentally and theoretically. From residual gas analysis, it is strongly evidenced that CH3 radicals from the organic materials in the paste deteriorate emission properties. Based on ab initio methods, it is found that CH3 radicals can increase electrical resistance of the nanotube an...

The carbon nanotube-liquid-crystal (CNT-LC) nanophotonic device is a class of device based on the hybrid combination of a sparse array of multiwall carbon nanotube electrodes grown on a silicon surface in a liquid-crystal cell. The multiwall carbon nanotubes act as individual electrode sites that spawn an electric-field profile, dictating the refractive index profile within the liquid crystal a...

Despite many advances in carbon nanotube (CNT) research, several issues continue to plague the field with regard to the construction of well-defined hybrid CNT materials. Regiospecific covalent functionalization, nonspecific surface absorption, and carbon nanotube aggregation/bundling present major difficulties when working with these materials. In this communication, we circumvent these proble...

Energy transfer in noncovalently bound porphyrin/carbon nanotube compounds is investigated at the single-nanocompound scale. Excitation spectroscopy of the luminescence of the nanotube shows two resonances arising from intrinsic excitation of the nanotube and from energy transfer from the porphyrin. Polarization diagrams show that both resonances are highly anisotropic, with a preferred directi...

In this work, we report the first direct experimental observations of carbon nanotubes (CNT) field emitting in an oxygen environment, using aberration-corrected environmental transmission electron microscopy in combination with an electrical biasing specimen holder under low-dose, field-free imaging conditions. Our studies show that while the CNTs remain stable during high vacuum field emission...

Individual multiwalled carbon nanotube field emitters were prepared in a scanning electron microscope. The angular current density, energy spectra, and the emission stability of the field-emitted electrons were measured. An estimate of the electron source brightness was extracted from the measurements. The results show that carbon nanotubes are promising candidates to replace existing sources i...

Electrical transport measurements were used to study device behavior that results from the interplay of defects and inadvertent contact variance that develops in as-grown semiconducting single wall carbon nanotube devices with nominally identical Au contacts. The transport measurements reveal that as-grown nanotubes contain defects that limit the performance of field-effect transistors with ohm...

In this paper, experimental and Finite Element Methods have been used to determine mechanical properties of nanocomposites. Standard tensile and compression samples with 0.0, 0.15, 0.25, 0.35, 0.45, and 0.55 weight fraction of Multi-Walled Carbon Nanotube (MWCNT) were prepared and tested. Nanotube weight fraction was varied to investigate the effects of nanotube weight fraction on nanocomposite...