Nano Express

Nanoscale Research Letters

, Volume 4, Issue 5, pp 431-436

Open Access This content is freely available online to anyone, anywhere at any time.

Field Emission and Radial Distribution Function Studies of Fractal-like Amorphous Carbon Nanotips

  • F. SoláAffiliated withDepartment of Physics, Institute for Functional Nanomaterials, University of Puerto Rico
  • , A. Biaggi-LabiosaAffiliated withDepartment of Physics, Institute for Functional Nanomaterials, University of Puerto Rico
  • , L. F. FonsecaAffiliated withDepartment of Physics, Institute for Functional Nanomaterials, University of Puerto Rico Email author 
  • , O. RestoAffiliated withDepartment of Physics, Institute for Functional Nanomaterials, University of Puerto Rico
  • , M. Lebrón-ColónAffiliated withPolymeric Materials Branch, Materials and Structures Division, National Aeronautics and Space Administration Glenn Research Center
  • , M. A. MeadorAffiliated withPolymeric Materials Branch, Materials and Structures Division, National Aeronautics and Space Administration Glenn Research Center

Abstract

The short-range order of individual fractal-like amorphous carbon nanotips was investigated by means of energy-filtered electron diffraction in a transmission electron microscope (TEM). The nanostructures were grown in porous silicon substrates in situ within the TEM by the electron beam-induced deposition method. The structure factor S(k) and the reduced radial distribution function G(r) were calculated. From these calculations a bond angle of 124° was obtained which suggests a distorted graphitic structure. Field emission was obtained from individual nanostructures using two micromanipulators with sub-nanometer positioning resolution. A theoretical three-stage model that accounts for the geometry of the nanostructures provides a value for the field enhancement factor close to the one obtained experimentally from the Fowler-Nordheim law.

Keywords

Carbon nanotips Graphite-like a-C EELS EFED Field emission