Revealing the Impact of Catalyst Phase Transition on Carbon Nanotube Growth by in Situ Raman Spectroscopy

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• 作者：Rahul Rao ; Neal Pierce ; David Liptak ; Daylond Hooper ; Gordon Sargent ; S. Lee Semiatin ; Stefano Curtarolo ; Avetik R. Harutyunyan ; Benji Maruyama
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：February 26, 2013
• 年：2013
• 卷：7
• 期：2
• 页码：1100-1107
• 全文大小：435K
• 年卷期：v.7,no.2(February 26, 2013)
• ISSN：1936-086X

文摘

The physical state of the catalyst and its impact on the growth of single-walled carbon nanotubes (SWNTs) is the subject of a long-standing debate. We addressed it here using in situ Raman spectroscopy to measure Fe and Ni catalyst lifetimes during the growth of individual SWNTs across a wide range of temperatures (500鈥?400 掳C). The temperature dependence of the Fe catalyst lifetimes underwent a sharp increase around 1100 掳C due to a solid-to-liquid phase transition. By comparing experimental results with the metal鈥揷arbon phase diagrams, we prove that SWNTs can grow from solid and liquid phase-catalysts, depending on the temperature.

Keywords:

carbon nanotubes; CVD growth; phase transition; Raman spectroscopy; in situ