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Microstructure and Electron Field Emission study of diamond nanorod decorated a-SiO2 nanowires by microwave Ar-CH4/H2 plasma chemical vapour deposition with addition of N2

Singh, M.K.S. ; Titus, E.T. ; Willinger, M.G.W. ; Mendes, J. C.

Diamond and Related Materials Vol. 18, Nº 5-8, pp. 865 - 869, May, 2009.

ISSN (print): 0925-9635
ISSN (online):

Journal Impact Factor: 1,913 (in 2011)

Digital Object Identifier: 10.1016/j.diamond.2009.02.021

In our recent paper [M. K. Singh et al., Chem. Mater. 20 (2008) 1725], we reported the fabrication of Nanocrystalline diamond (NCD) fibers by template (a-SiO2 nanowires) technique. Our present work demonstrate that the addition of nitrogen of 20% by volume in the reaction gas during synthesis induce the formation of feather-like morphology of NCD on a-SiO2 nanowires. The feather-like morphology consists oriented diamond nanorods surrounded by an sp2-bonded carbon sheath. These have been characterized by Scanning Electron Microscopy, Transmission Electron Microscopy (high-resolution mode) and Micro-Raman spectroscopy. Electron field emission (EFE) of as-synthesized NCD fibers (with 20% N2 addition) was observed with a threshold field of 3.5 V/µm which is quite less in comparison to previous grown NCD fibers and the current density at 10 V/µm increases around 20 times with 20% nitrogen doping in the gas source during synthesis. This may be because each diamond nanorod is enveloped in a sheath of sp2-bonded nanocarbons which provides a conducting path for electron emission.