Stability of carbon nanotubes under electric field studied by scanning electron microscopy

Abstract

The influence of an applied electric field on carbon nanotubes protruding from a surface was investigated in situ using a high-resolution scanning electron microscopy. Under the applied electric field, the nanotubes flexed to orient themselves parallel to the electric field lines. For moderate field strengths below the electron field emission threshold, the flexed nanotubes relaxed back to their original shapes after the electric field was removed. However, when high electron field emission currents were extracted from the nanotubes, they were permanently deformed, leaving them aligned to the electric field direction after the electric field was removed. For high currents, the length of the carbon nanotubes were found to be shortened after field emission lasted for a period of time.