Influence of Chemical Vapor Deposition Conditions on the Morphology of TiC Micro- and Nanostructures

Abstract

The synthesis of TiC micro- and nanofibers by chemical vapor deposition from titanium tetrachloride and carbon-containing substances such as toluene and carbon tetrachloride, using Fe, Co, Ni, and Al catalysts, in the temperature range 1000–1200°C was studied. The optimal temperature ranges for the synthesis of TiC micro- and nanofibers were found to be 1000–1100°C with titanium tetrachloride and toluene as the carbon source and 1150–1200°C with titanium tetrachloride and carbon tetrachloride, which is consistent with the thermodynamic calculations. Nickel was identified as the most suitable catalyst for the synthesis. The TiC micro- and nanofibers grew through the vapor–liquid–solid mechanism. The TiC nanofibers were predominantly synthesized at 1000–1100°C, while microfibers with diameters reaching several micrometers were produced at higher temperatures. When nickel was used as the catalyst, the fibers grew in the form of tufts or needles. Thickened regions, microcrystals, and nanofibers developed on individual TiC microfibers. For the first time, rod-like phases were produced by chemical vapor deposition on an aluminum substrate, which can be interpreted as the MAX Ti₃AlC₂ phase. When iron powder was used as the catalyst, a two-dimensional titanium carbide phase grew, regardless of the carbon source. Dew-like droplets were formed on titanium carbide fibers grown on nickel or cobalt catalysts. Their composition can be attributed to the corresponding eutectics in the Ti–Ni and Ti–Co systems.