Direct observation of carbon nanotube growth by Environmental Transmission Electronic Microscopy

M. Picher, P.A. Lin, J. Winterstein, S. Blankenship, R. Sharma
National Institute of Standards and Technology, US

Keywords: nanotube, ETEM, CVD, growth mechanism

Summary:

The first stages of nanotube life, e.g. the activation of a catalytic nanoparticle, followed by the segregation and the lift-off of a hemispherical cap are obviously critical steps which strongly influence the final yield and the type of structures grown. We have employed in situ high-resolution transmission electron microscopy (HRTEM) combined with electron energy loss (EELS) and Raman spectroscopies in order to probe the first stages of growth. An original pulsed gas introduction protocol is used in order to artificially increase the time resolution of the study. We report on the critical chemical and physical changes occurring at the nanoparticle scale for different catalytic systems.