scholarly journals Synthesis and Optical Characterization of Carbon Nanofibers

Radio frequency plasma enhanced chemical vapor deposition technique has been used to synthesized graphitic carbon nanofibers thin films. Ni catalyst in thin film form used for the synthesis of carbon nanofibers. The deposition temperature of the substrate has been varied from 500 - 600 0C. The morphology of the CNF thin films changed with the variation of substrate temperature. The graphitic phase of the synthesized carbon nanofibers has confirmed by X-ray diffraction patterns analyses. Field emission scanning electron microscopic studies showed fibrous structure in the films. The length of the carbon nanofibers few micrometers and the diameter range 300-400 nm. The different vibrational modes of carbon nanofibers analyzed using Fourier transformed infrared spectroscopy measurements. Photoluminescence of the carbon nanofibers have also been studied which showed a strong emission peak at 468 nm.

2021 ◽  
Vol 6 (20) ◽  
pp. 4867-4873
Author(s):  
Bhagyashri Todankar ◽  
Pradeep Desai ◽  
Ajinkya K. Ranade ◽  
Tharangattu N. Narayanan ◽  
Masaki Tanemura ◽  
...  

2016 ◽  
Vol 11 (3) ◽  
pp. 62-71
Author(s):  
Gulmira Partizan ◽  
Batyr Mansurov ◽  
Botagoz Medyanova ◽  
Аizhan Koshanova ◽  
Madina Mansurova ◽  
...  

This article presents the results of experiments on the synthesis of carbon nanofibers by thermal chemical vapor deposition using copper nanopowders obtained by electric explosion of wire as catalysts. Stable growth of carbon nanofibers was carried out at temperatures significantly lower than normally used. The process parameters that are optimal for low-temperature growth of carbon nanofibers have been identified during the performed experiments. The synthesized samples have different diameters and morphology (from spiral to direct). Copper clusters are both at the ends and inside the fibers. The results of IR spectroscopy indicate that the structure of the obtained carbon nanofibers is polymeric. X-ray analysis revealed the presence of a halo on the diffraction patterns at small values of the angle 2θ, which proves that the grown structures have an amorphous nature. There are no groups that are responsible for long-range order in all Raman spectra. Studies by transmission electron microscopy showed that nanostructures do not have an internal channel and nanofibers are solid.


2005 ◽  
Vol 862 ◽  
Author(s):  
A. R. Middya ◽  
J-J. Liang ◽  
K. Ghosh

AbstractIn this work, we report on next-generation hot wire chemical vapor deposition technique, we call it ceramics hot-wire CVD. Using a new concept of rectangular ceramics filament holder and “confinement of thermal radiation from the filament”, a “new form” of polycrystalline silicon thin films has been developed at low temperature (˜ 250°C). The grains are found to be symmetrically distributed in array along the parallel lines, in (111) direction. On the surface of individual grains, “five-fold” and “six-fold” symmetries have been observed and we suspect that we developed “buckyball” type “giant silicon molecular solids” with different crystalline silicon lattice other than standard single-crystal silicon structure. We observed rarely found “icosaderal” symmetry in silicon thin films. This hypothesis has been supported by multiple Raman active transverse optical modes and the crystallographic structure analyzed by X-ray diffraction.


2014 ◽  
Vol 896 ◽  
pp. 192-196 ◽  
Author(s):  
Aip Saripudin ◽  
H. Saragih ◽  
Khairurrijal ◽  
Khairurrijal ◽  
Pepen Arifin

Co:TiO2 (cobalt-doped titanium dioxide) thin films have been deposited on the n-type Si (100) substrate at the temperatures range of 325°C 450°C using MOCVD (metal organic chemical vapor deposition) technique. We investigated the effect of growth temperature on the structural and morphological quality of Co:TiO2 thin films. The structure of Co:TiO2 thin films were characterized by XRD while the morphology and the thickness of films were characterized by SEM. The XRD results reveal that all films show the anatase structure and the dominant orientation of anatase phase depends on the growth temperature. The grain size of crystal increases as the growth temperature increases. We also reveal that the growth rate of Co:TiO2 film has a maximum value at the growth temperature of 400°C.


2007 ◽  
Vol 989 ◽  
Author(s):  
Yasutoshi YASHIKI ◽  
Seiichi KOUKETSU ◽  
Shinsuke MIYAJIMA ◽  
Akira YAMADA ◽  
Makoto KONAGAI

AbstractEffects of boron doping on microcrystalline germanium carbon alloy (μc-Ge1-xCx:H) thin films have been investigated. We deposited boron-doped p-type μc-Ge1-xCx:H thin films by hot-wire chemical vapor deposition technique using hydrogen diluted monomethylgermane (MMG) and diborane (B2H6). A dark conductivity of 1.3 S/cm and carrier concentration of 1.7 x 1020 cm-3 were achieved with B2H6/MMG ratio of 0.1. Furthermore, the activation energy decreased from 0.37 to 0.037 eV with increasing B2H6/MMG ratio from 0 to 0.1. We also fabricated p-type μc-Ge1-xCx:H/n-type c-Si heterojunction diodes. The diodes showed rectifying characteristics. The typical ideality factor and rectifying ratio were 1.4 and 3.7 x 103 at ¡Ó 0.5 V, respectively.


2002 ◽  
Vol 756 ◽  
Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Sergey Yarmolenko ◽  
Qiuming Wei

ABSTRACTLiquid fuel combustion chemical vapor deposition technique was successfully used for YSZ thin film processing. The nucleation rates were obtained for the samples processed at different temperatures and total-metal-concentrations in the liquid fuel. An optimum substrate temperature was found for the highest nucleation rate. The nucleation rate was increased with the total-metal-concentration. Structural evolution of the thin film in the early processing stage was studied with regard to the formation of nuclei, crystallites and final crystals on the films. The films were found to be affected by high temperature annealing. The crystals and the thin films were characterized with scanning electron microscopy.


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