촉매 화학기상증착 공정에서 온도구배 설정을 통한타이타늄 기판에서의 CNT 성장 거동

Abstract

In this study, modified catalytic chemical vapor deposition (CCVD) method was applied to control the CNTs (carbon nanotubes) growth. Since titanium (Ti) substrate and iron (Fe) catalysts react one another and form a new phase (Fe2TiO5) above 700℃, the decrease of CNT yield above 800℃ where methane gas decomposes is inevitable under common CCVD method. Therefore, we synthesized CNTs on the Ti substrate by dividing the tube furnace into two sections (left and right) and heating them to different temperatures each. The reactant gas flew through from the end of the right tube furnace while the Ti substrate was placed in the center of the left tube furnace. When the CNT growth temperature was set 700/950℃ (left/right), CNTs with high yield were observed. Also, by examining the micro-structure of CNTs of 700/950℃, it was confirmed that CNTs show the bamboo-like structure.