Control of Cobalt Catalyst Thin Film Thickness by Varying Spin Speed in Spin Coating towards Carbon Nanotube Growth

2015 ◽  
Vol 761 ◽  
pp. 421-425 ◽  
Author(s):  
Nor Najihah Zulkapli ◽  
Mohd Edeerozey Abd Manaf ◽  
Hairul Effendy Ab Maulod ◽  
Nor Syafira Abdul Manaf ◽  
Raja Noor Amalina Raja Seman ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carbon Nanotubes ◽  
Spin Coating ◽  
Chemical Vapor ◽  
Cobalt Acetate ◽  
Metal Catalyst ◽  
Co Catalyst ◽  
Spin Speed ◽  
Walled Carbon Nanotubes

Cobalt (Co) catalyst thin film is an active metal catalyst that can be very helpful to grow carbon nanotubes (CNTs). The catalyst thin films were prepared on silicon wafers by spin coating the solution of cobalt acetate tetrahydrate and ethanol. The effects of different spin speed parameter during the spin coating process were investigated. The findings showed that the optimum thickness of the Co catalyst thin films, i.e., 12.1 nm, was obtained at the highest spin speed of 8000 rpm. The uniformity of the thin films was also found to increase with increasing spin speed. The study also demonstrated that single-walled carbon nanotubes could be grown from Co catalyst particles after the catalytic chemical vapor deposition of ethanol. The particle and thickness analysis, as performed by means of FESEM while the existence of CNTs, was performed by Raman spectroscopy.

Thin Films of Liquid Crystalline Phthalocyanines and their its Composites with Single-Walled Carbon Nanotubes: Properties and Alignment

2012 ◽  
Vol 531-532 ◽  
pp. 337-341
Author(s):  
Tamara Basova ◽  
Aliye Aslı Esenpinar ◽  
Sinem Tuncel ◽  
Mahmut Durmuş ◽  
Ayşe Gül Gürek ◽  
...  
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Spin Coating ◽  
Liquid Crystalline ◽  
Copper Phthalocyanine ◽  
Single Walled Carbon Nanotubes ◽  
Polarizing Microscopy ◽  
Single Walled Carbon ◽  
Polarized Raman ◽  
Walled Carbon Nanotubes

In this study, liquid crystalline copper phthalocyanine and single walled carbon nanotubes were dispersed in solution to prepare novel composites. Thin films of these composites prepared by solving of the composite in dimetylformamide and then by spin coating the solution onto the substrates were studied by the methods of polarizing microscopy, polarized Raman and optical absorption spectroscopies. It was shown that pure CuPcR4forms the films with a herringbone arrangement of phthalocyanine molecules within adjacent columns. An addition of carbon nanotubes (0.5-2 wt %) to CuPcR4leads to formation of the films with edge-on orientation of the molecules. The higher conductivity values were found for the films of phthalocyanine containing SWCNT. The lateral conductivity tends to decrease with the increase of SWCNT concentration from 0.5 to 2 wt %.

scholarly journals The Reduction Temperature Effect of Fe–Co/MgO Catalyst on Characteristics of Multi-Walled Carbon Nanotubes

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 361 ◽  
Author(s):  
Paul Kim ◽  
Cheol Lee
Keyword(s):  
Carbon Nanotubes ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Diameter Distribution ◽  
Metal Catalyst ◽  
Reduction Temperature ◽  
Raman Analysis ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Diameters and crystallinity of multi-walled carbon nanotubes (MWCNTs) dependent on reduction temperature of the Fe–Co/MgO catalyst were investigated. MWCNTs were synthesized by catalytic chemical vapor depositing and the Fe–Co/MgO catalyst was fabricated by using a sol-gel method. According to Raman analysis, transmission electron microscopy and thermogravimetric analysis, the diameter distribution of MWCNTs was broadened with increasing reduction temperature of the Fe–Co/MgO catalyst and crystallinity was improved. The above results are attributed to an increased size and enhanced crystallinity of metal catalyst particles by increasing reduction temperature.

The Role of Metal Catalyst in Near Ambient Hydrogen Adsorption on Multi-walled Carbon Nanotubes

2004 ◽  
Vol 837 ◽  
Author(s):  
Yong-Won Lee ◽  
Rohit Deshpande ◽  
Anne C. Dillon ◽  
Michael J. Hebe ◽  
Hongjie Dai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Adsorption ◽  
Chemical Vapor ◽  
Metal Catalyst ◽  
Ambient Conditions ◽  
Multiwalled Carbon ◽  
Multi Walled Carbon Nanotubes ◽  
Methane Source ◽  
Temperature Programmed ◽  
Walled Carbon Nanotubes

ABSTRACTMultiwalled carbon nanotubes (MWNTs) were continuously synthesized by hot wire chemical vapor deposition (HWCVD) using a methane source catalyzed by metal-organic ferrocene. The microstructure of the MWNTs and the catalyst particles were subsequently characterized with transmission electron microscopy which identified three different phases, i.e., bcc α-Fe, fcc γ-Fe and orthorhombic Fe3C. The hydrogen storage capacity of MWNTs was determined with temperature-programmed desorption (TPD) technique. Hydrogen adsorption at near ambient conditions was observed only in as-synthesized MWNTs containing iron particles and was dramatically increased after hydrogen reducing treatment. Possible adsorption mechanism was also discussed.

Conductivity of Thin Films Based on Single-Walled Carbon Nanotubes Grown by Chemical Vapor Deposition

2015 ◽  
Vol 57 (11) ◽  
pp. 1600-1603 ◽  
Author(s):  
M. S. Rybakov ◽  
A. V. Kosobutsky ◽  
О. G. Sevostyanov ◽  
D. М. Russakov ◽  
М. V. Lomakin ◽  
...  
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Conductivity Of Thin Films

scholarly journals Экспериментальное исследование коэффициента теплопроводности в тонких пленках на основе одностенных углеродных нанотрубок

2020 ◽  
Vol 62 (6) ◽  
pp. 960
Author(s):  
И.А. Тамбасов ◽  
А.С. Воронин ◽  
Н.П. Евсевская ◽  
Ю.М. Кузнецов ◽  
А.В. Лукьяненко ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermal Conductivity Coefficient ◽  
Single Walled Carbon Nanotubes ◽  
3Ω Method ◽  
Vacuum Filtration ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Thin films based on single walled carbon nanotubes with a thickness of 11 ± 3 to 157 ± 18 nm were formed using vacuum filtration. The thermal conductivity coefficient in thin films was studied depending on the thickness and temperature up to 450 K using the 3ω method. It was found that, in the region of 49 nm, the supplied heat from the gold strip began to efficiently propagate into the plane of the thin film. The thermal conductivity coefficient for thin films with a thickness of 49 ± 8 nm was measured according to the 3ω method for bulk samples. It was found that the thermal conductivity in thin films based on single walled carbon nanotubes strongly depends on the thickness and temperature. The thermal conductivity increased sharply (~ 60 times) with increasing thickness from 11 ± 3 to 65 ± 4 nm. In addition, it was revealed that the thermal conductivity coefficient for 157 ± 18 nm thin film rapidly decreased from 211 ± 11 to 27.5 ± 1.4 W · m-1 · K-1 for 300 and 450 K, respectively.

scholarly journals Growth mechanisms of single-wall carbon nanotubes in a chemical vapor deposition (CVD) process on Fe/Mo-Al catalyst

2013 ◽  
Vol 16 (1) ◽  
pp. 72-80
Author(s):  
Thang Van Le
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Metal Catalyst ◽  
Formation Mechanisms ◽  
Growth Mechanisms ◽  
Cvd Growth ◽  
Walled Carbon Nanotubes

The formation mechanisms involved in the growth of single-walled carbon nanotubes (SWNTs) by chemical vapor deposition (CVD) was studied. Transmission electron microscopy (TEM) was used to analyze the encapsulated metal catalyst particles found within the tubes, and the dimensions and location of these particles was determined. SWNTs were found to have encapsulated particles in the end of tubes, with large length to diameter ratios. As a result of these observations, we concluded that SWNTs are formed via an open-ended, base-growth mechanism (VLS mechanism). Additionally, we have demonstrated the formation of two kinds of bundles of SWNTs (Parallel bundles and as-rope bundles). SWNTs grown with thermal CVD on Fe/Mo-Al catalyst did not contain similar elongated particles or particles along the middle of the tubes, indicating that these new growth mechanisms are only applicable in the case of tubes grown via vapor phase CVD growth methods.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

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