Papers by Author: Sovan Kumar Panda

Abstract: The effect of Fe and Ni catalysts on the synthesis of carbon nanotubes (CNTs) using atmospheric pressure chemical vapor deposition (APCVD) was investigated. Distribution of the catalyst particles over the Si substrate was analyzed by atomic force microscopy (AFM). Characterization by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopic measurements over the grown species is reported. The study clearly shows that the catalyst strongly influences morphology and microstructure of the grown CNTs.

Abstract: β-SiC nanowires have been synthesized on etch-patterned wafers in a chemical vapor deposition (CVD) system without using any metal catalyst. The nanowires were grown selectively inside the ‘V-groove’ of etch-patterned silicon (110) substrate which was used as a template for nanostructure growth. Nanowire growth was hardly found on the sample which was not previously etched. The nanowires have a core-sheath structure with the SiC core surrounded by an amorphous SiO2 sheath layer. The etching of the patterned Si (110) wafers was carried out by a 50 % aqueous KOH solution. The SiC growth was performed in a resistively heated atmospheric pressure chemical vapor deposition (APCVD) system by using hexamethyldisilane (HMDS) as the single source for Si and C at 1150oC. The as-grown samples and the patterned wafers were characterized by field emission electron microscopy, energy dispersive x-ray spectroscopy, X-ray diffraction, micro-Raman spectroscopy and Fourier transform infrared spectroscopy. Etching is one of the key factors for nanostructure growth and the patterning in the wafer provides selectivity. The growth process was governed by vapor-solid (VS) mechanism.