We report the controlled formation and characterization of heterojunctions between carbon nanotubes and different metal nanocrystals (Fe, Co, Ni, and FeCo). The heterojunctions are formed from metal-filled multiwall carbon nanotubes (MWNTs) via intense electron beam irradiation at temperatures in the range of 450-700 degrees C and observed in situ in a transmission electron microscope. Under ir...

Bending-mode vibrations of carbon nanotube resonators were mechanically detected in air at atmospheric pressure by means of a novel scanning force microscopy method. The fundamental and higher order bending eigenmodes were imaged at up to 3.1 GHz with subnanometer resolution in vibration amplitude. The resonance frequency and the eigenmode shape of multiwall nanotubes are consistent with the el...

This research demonstrates the capability of controlled, focused ion beam (FIB)–assisted tailoring of morphologies in both multiwall carbon nanotubes (CNTs) and Y junction nonlinear CNT systems through defect engineering. We have shown that a 30 keV FIB Ga ion beam at low ion milling currents of 1 pA can be used to partially reduce the CNT diameter, to provide electrical conduction bottleneck m...

The transmission electron microscopy images of in situ prepared multiwall carbon nanotubes MWNTs and polyaniline PANI composites show that nanotubes are well dispersed in aqueous medium, and the nanofibers of PANI facilitate intertube transport. Although low temperature transport indicates variable range hopping VRH mechanism, the dc and ac conductivity become temperature independent as the MWN...

Thermal conductivity (kappa) of isolated carbon nanotubes (CNTs) is higher than the kappa of diamond; however, in this Letter we show that the kappa of a packed bed of three-dimensional random networks of single and multiwall CNTs is smaller than that of thermally insulating amorphous polymers. The thermoelectric power (Sigma) of the random network of CNTs was also measured. The Sigma of a sing...

A large effort is being made to develop nanosorbents with tunable surface chemistry for enhanced adsorption affinity and selectivity toward target organic contaminants. Heteroatom N-doped multiwall carbon nanotubes (N-MCNT) were synthesized by chemical vapor deposition of pyridine and were further investigated for the adsorptive removal of several aromatic chemicals varying in electronic donor ...

In this paper functionalized multiwall carbon nanotubes (FMWCNT) were modified using doxycycline, containing reactable nitrogen, which can attach chemically to functionalized MWCNT. The synthesized nano compounds were characterized by Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. These spectrums proved the existence of nitrogen atoms of amide functional groups. The mor...