Carbon Nanostructures Under the Electron Beam: Formation of New Structures and In-Situ Study of Radiation-Induced Processes

TLDR: In this paper, the authors focus on exploring recent results of TEM use, either in its High-Resolution mode (HRTEM) or in its scanning mode (STEM), as an active, dynamic probe station.

Abstract: Transmission Electron Microscopy (TEM) has been demonstrated to be a well-suited technique for characterizing and studying in-situ phenomena in materials at the nanometer scale, as proved by several demonstrations involving carbon nanotubes [1]. For example, the feasibility of confining different elements in the cavity of the nanotubes, like C60, gases and fluid systems, provides the opportunity of studying dynamically at the nanometer scale specific in-situ induced-processes like fullerene coalescence, local gas pressure increase and liquid/gas movement inside the nanotubes. In this chapter we will focus our attention on exploring recent results of TEM use, either in its High-Resolution mode (HRTEM) or in its scanning mode (STEM), as an active, dynamic probe station. The first part of the chapter reviews the electron irradiation studies carried out on carbon materials, like graphite and nanotubes. Then, several in-situ experiments like thermal annealing, electron beam irradiation and time resolved electron energy-loss spectroscopy show the capacity of the TEM to create new carbon based nanostructures (for example, onion-like structures, CNx nano-islands etc. within C nanotubes) and nanowires, while simultaneously monitoring the processes. Finally, the efficiency of HRTEM dynamical studies for understanding the formation process of novel carbon nanostructures, for investigating dynamic phenomena such as the coalescence of SWNTs and for studying the dynamic aspect of fluid transport in the nanotubes will be discussed.