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Carbon nanotubes (CNTs) have been the focus of considerable attention because of the many possible applications in nanostructure, super strong materials, semiconductors, electron emitting devices, and gas sensor materials. However when considering an electric device to be used for environmental application, many conditions must be satisfied such as low preparation costs, the wide area, preparation system must be simple and safe and so on. In regards to CNTs, several process methods such as arc discharge, chemical vapor deposition (CVD) and pulsed laser ablation have been used to produce them. Whatever method is used, it isn't easy to apply the catalyst metal, which is necessary for the CNTs growth. However, at present, not only the function of the catalyst isn't understand well but also the growth mechanism of the CNTs isn't made clear, either. To prepare CNTs, we applied a catalysis organ-metal solution (metal resinate) to a substrate and then it was burned out. This method is very unique, and it may never have been used as the catalyst for producing nanotubes. We had previously developed a process using nano size dots (diameter = 40 nm ~ 100 nm) of catalytic metal on silicon or quartz glass substrate preparation. In this study, we developed a new pulsed heating furnace by using high collection nonimaging optics which can rapidly rise up and down the substrate temperature with a simple method to apply carbon source that is only mixed graphite powder to the metal resinate. It is effective from the viewpoint of the exhaust gas as well because this CVD system could operate in pure oxygen or atmospheric ambient condition. A substrate holder was heated with focused light of a halogen lump. It confirmed that CNTs grew by this equipment even in the short time (around 1 ~ 3 min) with a very simple single-step optical CVD process. |