Raman spectroscopy and field-emission properties of CVD-grown carbon-nanotube films

Sveningsson, Martin; Morjan, Raluca Elena; Nerushev, Oleg; Sato, Yoshihito; Bäckström, Joakim; Campbell, Eleanor E. B.; Rohmund, F.

doi:10.1007/s003390100923

Cited by 198 publications

(109 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The Raman band emerging in low wavenumbers region of Furthermore, pyrolytic carbon particles deposited on nanotubes also contributed to the D-band intensity [33,34]. In the present system, G band is at higher intensity, indicating that the CNTs are graphitized, which is in agreement with the result of TEM observation.…”

Section: Raman Spectroscopysupporting

confidence: 90%

Towards the low temperature growth of uniform diameter multi walled carbon nanotubes by catalytic chemical vapour deposition technique

Somanathan

Pandurangan

2010

Nano-Micro Lett

View full text Add to dashboard Cite

Mesoporous MCM-41 molecular sieves containing f-block transition elements (gadolinium) with various Si/Gd ratios (50, 75 and 100) were synthesised by a hydrothermal method. Their mesoporous structure was confirmed by X-ray diffraction, nitrogen sorption studies, thermogravimetric analysis, scanning and transmission electron microscopy. The local environment of Gd in the material was studied by electron paramagnetic resonance. The compatibility of the catalyst for the synthesis of uniform diameter CNTs by varying the temperature from 400 to 650°C with fixed flow rates of N 2 and C 2 H 2 (140 ml/min and 40 ml/min, respectively). The product is mostly metal containing thin MWCNTs with diameter of 10a20 nm. Characterisation shows that a combination of Gd-MCM-41 (100) catalyst gives a high yield of high quality MWCNTs under optimum growth conditions. [7]. The major drawback of arc discharge and laser evaporation methods is that they are extremely uncontrolled in terms of process parameters, resulting in CNTs that contains significant fractions of unwanted material and that are difficult to manipulate and assemble in specific designs. CVD method is based on the thermal decomposition of hydrocarbon compounds over transition metal catalyst particles.It appears to be a simple and economic technique to synthesize this kind of material at a low temperature, ambient pressure and it represents the best hope for large scale production.To date, all the metal-catalyzed CNT growth studies have mainly focused on transition metals. Curiously, f-block transition elements also referred to as inner transition elements have still not been well explored. One reason could be that inner transition elements are not known to be highly catalytic as the transition elements. It has also been suggested that lanthanoids such as gadolinium and europium exhibit insufficient carbon solubility, slow carbon diffusion, and limited carbide formation to catalyze CNT growth [8]. Recently, gadolinium and europium were used

show abstract

Section: Raman Spectroscopysupporting

confidence: 90%

Towards the low temperature growth of uniform diameter multi walled carbon nanotubes by catalytic chemical vapour deposition technique

Somanathan

Pandurangan

2010

Nano-Micro Lett

View full text Add to dashboard Cite

show abstract

“…In the calculation of the field enhancement factor, the work function of the CNT was assumed to be equal to that of graphite (5 eV) [32]. The ?value of our VA thin-MWCNTs was calculated to be 3774, which was larger than those of the VA MWCNTs reported previously [33]. This is probably attributed to the smaller tip radius of our VA thin-MWCNTs.…”

Section: ⅱ Experimentscontrasting

confidence: 72%

Synthesis of vertically aligned thin multi-walled carbon nanotubes on silicon substrates using catalytic chemical vapor deposition and their field emission properties

Jung¹,

Choi²,

Lee

2008

Journal of the Korean Vacuum Society

View full text Add to dashboard Cite

We have succeeded in synthesizing vertically aligned thin multi-walled carbon nanotubes (VA thin-MWCNTs) by a catalytic chemical vapor deposition (CCVD) method onto Fe/Al thin film deposited on a Si wafers using an optimum amount of hydrogen sulfide (H 2 S) additive. Scanning electron microscope (SEM) images revealed that the as-synthesized CNT arrays were vertically well-oriented perpendicular to the substrate with relatively uniform length. Transmission electron microscope (TEM) observations indicated that the as-grown CNTs were nearly catalyst-free thin-MWCNTs with small outer diameters of less than 10nm.The average wall number is about 5. We suggested a possible growth mechanism of the VA thin-MWCNT arrays. The VA thin-MWCNTs showed a low turn-on electric field of about 1.1 V/μm at a current density of 0.1 μA/cm 2 and a high emission current density about 2.5 mA/cm 2 at a bias field of 2.7 V/μm. Moreover, the VA thin-MWCNTs presented better field emission stability without degradation over 20 hours (h) at the emission current density of about 1 mA/cm 2 .

show abstract

“…combined G+D modes and the overtone of the LO mode Kawashima, 1995;Shimada et al, 2005;Sveningsson et al, 2001;Tan, 2004). We note that the 2427 cm -1 (G*) band has also been assigned to other combination modes (Maultzsch et al, 2004) and is usually a weak feature in most sp 2 carbons (Tan, 2004;Yoon, 2009) but in our sample it is rather intense.…”

Section: Direct Irradiation Of Quartz Ampoulessupporting

confidence: 58%

Synthesis of Carbon Nanostructures by Microwave Irradiation

Vivas-Castro¹,

Rueda-Morales²,

Ortega-Cervantez³

et al. 2011

Carbon Nanotubes - Synthesis, Characterization, Applications

View full text Add to dashboard Cite

Raman spectroscopy and field-emission properties of CVD-grown carbon-nanotube films

Cited by 198 publications

References 2 publications

Towards the low temperature growth of uniform diameter multi walled carbon nanotubes by catalytic chemical vapour deposition technique

Towards the low temperature growth of uniform diameter multi walled carbon nanotubes by catalytic chemical vapour deposition technique

Synthesis of vertically aligned thin multi-walled carbon nanotubes on silicon substrates using catalytic chemical vapor deposition and their field emission properties

Synthesis of Carbon Nanostructures by Microwave Irradiation

Contact Info

Product

Resources

About