標題: Effect of Temperature Gradient Direction in the Catalyst Nanoparticle on CNTs Growth Mode
作者: Lo, An-Ya
Liu, Shang-Bin
Kuo, Cheng-Tzu
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: CNTs;Growth mechanism;Base-growth;Tip-growth;CVD
公開日期: 1-九月-2010
摘要: To improve the understanding on CNT growth modes, the various processes, including thermal CVD, MP-CVD and ECR-CVD, have been used to deposit CNTs on nanoporous SBA-15 and Si wafer substrates with C(2)H(2) and H(2) as reaction gases. The experiments to vary process parameter of Delta T, defined as the vector quantities of temperature at catalyst top minus it at catalyst bottom, were carried out to demonstrate its effect on the CNT growth mode. The TEM and TGA analyses were used to characterize their growth modes and carbon yields of the processes. The results show that Delta T can be used to monitor the temperature gradient direction across the catalyst nanoparticle during the growth stage of CNTs. The results also indicate that the tip-growth CNTs, base-growth CNTs and onion-like carbon are generally fabricated under conditions of Delta T > 0, < 0 and similar to 0, respectively. Our proposed growth mechanisms can be successfully adopted to explain why the base- and tip-growth CNTs are common in thermal CVD and plasma-enhanced CVD processes, respectively. Furthermore, our experiments have also successfully demonstrated the possibility to vary Delta T to obtain the desired growth mode of CNTs by thermal or plasma-enhanced CVD systems for different applications.
URI: http://dx.doi.org/10.1007/s11671-010-9648-4
http://hdl.handle.net/11536/32233
ISSN: 1931-7573
DOI: 10.1007/s11671-010-9648-4
期刊: NANOSCALE RESEARCH LETTERS
Volume: 5
Issue: 9
起始頁: 1393
結束頁: 1402
顯示於類別:期刊論文


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  1. 000280846000004.pdf