Thermodynamics of the production of condensed phases in the chemical vapor deposition of ZrC in the ZrCl4–CH4–H2–Ar system

•Control of the composition of deposits via adjustment of precursor ratios•Carbon enrichment can be avoided using a low amount of argon diluting gas.•The deposition process is significantly influenced by the presence of hydrogen.

Production conditions of ZrC, Zr and C(graphite) condensed phases in the chemical vapor deposition process with ZrCl4–CH4–H2–Ar precursor system have been investigated based on thermodynamic analyses using the FactSage code. The yields of condensed phases have been examined as functions of the injected reactant ratios of ZrCl4/(ZrCl4 + CH4), H2/(ZrCl4 + CH4) and Ar/(ZrCl4 + CH4), the temperature and the pressure. The results show that the yields strongly depend on the molar ratios of the ZrCl4/(ZrCl4 + CH4) and H2/(ZrCl4 + CH4) injected reactant and on the temperature, but are insensitive to the inert gas Ar ratio and pressure. The co-deposition of ZrC with Zr or C(graphite) can be easily controlled by changing the ratios of ZrCl4/CH4 and H2/(ZrCl4 + CH4). Process conditions such as high input amount of H2, relatively low amount of Ar, low pressure and temperature above 1300 K are favorable for the deposition of ZrC. The results of this work will be helpful for further experimental investigation on different deposition conditions.