Journal of Crystal Growth, Vol.431, 64-71, 2015
Large-scale synthesis of TiC whiskers by carbothermal reduction with microcrystalline cellulose as the carbon source
TiC whiskers were synthesized by a typical chloride-assisted carbothermal reduction method with microcrystalline cellulose as a novel carbon source. When with nickel, the Vapor-Liquid-Solid (VLS) and Vapor-Solid (VS) mechanisms were confirmed to govern the whisker growth with different Lip morphologies. Systematic investigation of the sintering schedule revealed that two steps sintering favored the formation of whiskers (over 90 vol% yield) with a low oxygen content (4.322 angstrom of the lattice parameter). Unlike previous research, faceted TiC whiskers on the titanium oxide particles (Ti3O5) were epitaxially grown via the VS mechanism without catalyst (nickel). An effect of carbon sources (cellulose, chars and pyrolytic carbon black) on the morphology of TiC whiskers has been studied. A two-dimensional (2-D) nucleation on the Ti3O5 substrate and persistent absorption of growth adatoms on the {111} faces (at the tip) was proposed to explain the formation of TiC whisker. This study provided not only a new simple method for synthesizing TiC whiskers but also a new insight into the growth mode for TiC whiskers. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Crystal morphology;Nanostructures;Single crystal growth;Vapor phase epitaxy;Titanium compounds