Synthesis of sheathed carbon nanotube tips by the sol–gel technique

We describe the first elaboration of carbon nanotube tips (CN-tips) by the sol–gel technique. TheCN-tips consist of single carbon nanotubes (CNs) or bundles sheathed by a nanometric layer ofTiO2 fixed to the apexof aWbase tip and oriented along itsmajor axis. The straight-forward method potentially permits low cost batch fabrication. Structural analysis has been realized by transmission electron microscopy (TEM). These CN-tips are interesting for applications in applied surface science such as field emission (FE) sources and near fieldmicroscopy probes.Afirst field emission study has also been carried out showing that the TiO2 layer does not block FE. Relatively stable emission at voltages usual to FE from CNs at up to 0.8 mA current were obtained. # 2003 Elsevier B.V. All rights reserved.