| Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系碩博士班 === 94 === Abstract
We have reported previously very fast growth (13μm/min) of aligned carbon nanotubes (CNT) at low temperature (less than 370 ℃) in the presence of Fe-Si thin film catalyst (Jyh-Ming Ting, Kun-Hou Liao, “Low-temperature, Nonlinear Rapid Growth of Aligned Carbon Nanotubes, CPL, 2004). The very fast, low temperature growth was attributed to the addition of Si into Fe. However, further understanding of the relationship between the nature of the catalyst and the CNT growth requires additional studies. Among them, we have addressed in this study the characteristics the Fe-Si thin film catalyst. A co-sputtering deposition method was used to deposit Fe-Si thin films under different deposition conditions to obtain thin films with various characteristics. As-deposited Fe-Si film consists of bcc a-Fe with a preferred (110) orientation and amorphous Si. Hydrogen plasma etched Fe-Si films become particles having different kinds of compounds, depending on the composition or an amorphous Si core. Such a difference has a significant consequence on the growth of CNTs. The co-deposition parameters that were varied include working pressure, electrode distance, DC and RF power wattage, and deposition time. The resulting Fe-Si thin films were examined using high-resulotion transmission electron microscopy (HRTEM), energy dispersion of x-ray (EDX) analysis, grazing incident XRD (GIXRD) and scanning electron microscope (SEM). Fe-Si thin films exhibiting different thicknesses, compositions, crystallinity, microstructure, and topography were obtained. Selected Fe-Si thin films were also used for the growth of CNT using a microwave plasma chemical vapor deposition (MPCVD) method.
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