chemical vapor deposition (cvd) is one of the most popular methods for producing carbon nanotubes (cnts). the growth rate of cnts based on cvd technique is investigated by using a numerical model based on finite volume method. inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as carrier gas enters into a horizontal cvd reactor at atmospheric pressure. in thi...

the growth rate and uniformity of carbon nano tubes (cnts) based on chemical vapor deposition (cvd) technique is investigated by using a numerical model. in this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal cvd reactor at atmospheric pressure. based on the gas phase and surface reactions, released carbon...

This work provides comparative studies of a double -doped Al0.3Ga0.7As/InxGa1−xAs/GaAs symmetrically graded x = 0.15 → 0.2 → 0.15 doped-channel field-effect transistor DD-DCFET with respect to a conventional double -doped pseudomorphic high electron mobility transistor pHEMT and a conventional DCFET structure. All threes samples, grown by the low-pressure metallorganic chemical vapor deposition...

thin films of sno2 nanowires were successfully prepared by using chemical vapor deposition (cvd) process on quartz substrates. afterwards, a thin  layer of palladium (pd) as a catalyst was coated on top of nanowires. for the deposition of pd, a simple and low cost technique of spray pyrolysis was employed, which caused an intensive enhancement on the sensing response of fabricated sensors. prep...

carbon nanotubes were synthesized over a series of zn-containing fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °c using methane as a carbon source. catalysts were synthesized by keeping fe concentration constant and varying zn concentration to study the effects of zn. the catalysts were characterized using x – ray powder diffraction and n2 ...

the growth rate of carbon nanotubes in chemical vapor deposition is simulated by using a theoretical analysis of the phonon vibration of the system. simulations demonstrate that the growth rate of carbon nanotubes with larger diameters is smaller because of higher damping factors and carbon nanotube inertia. an optimum temperature for the growth rate is calculated for a carbon nanotube on fe ca...

in this study, we describe the growth of carbon nanotubes on commercial iron nanoparticles without carbon shell (fe (nm), size 2o3 and fe* (nm)/mgo) was carried out by mixing commercial fe* nanoparticles (as catalyst) with al2o3 and mgo powders (as supports)by using ball-milling method. the results show in spite of the fact that ball-milling process can have negative effects on diameter and mor...

chemical vapor deposition was employed to synthesize carbon nanotubes with ni-loaded mcm-41 and mcm-48 as catalysts and acetylene as precursor at 750°c. mesoporous ni mcm-41 and ni mcm-48 molecular sieves were synthesized by a hydrothermal method and were characterized by xrd and n2 adsorption isotherm. the catalytically synthesized carbon materials were characterized with raman spectroscopy, n...