Research Information System
Vacuum, vol.233, 2025 (SCI-Expanded)
Molybdenum carbide (Mo2C) distinguishes itself among transition metal carbides due to its high melting point, thermal stability, and hardness. The potential use of Mo2C in both hydrogen production as a catalyst for hydrogen evolution reaction, and as corrosion resistive material in bipolar plates of fuel cells, has increased further interest in growth and synthesis of Mo2C via various approaches. Mo2C thin films are generally synthesized by chemical vapor deposition method (CVD) at high temperatures in the literature. In this study, Mo2C thin films were synthesized via the Plasma Enhanced CVD (PECVD) method by carburization of precursor Mo thin films deposited on soda lime glass (SLG) substrates. The precursor SLG/Mo thin films, deposited via rf. magnetron sputtering were subjected to different carburization times under H2 and CH4 flow at a process temperature of 550 °C. Structural investigations have revealed that 60 min carburization leads to formation of ∼116 nm thick mixed phase (90.7 % orthorhombic and 9.3 % hexagonal) Mo2C-graphite composite structure over ∼490 nm thick Mo thin film. These results are attributed to the dynamics of the CVD process leading to formation of a more stable orthorhombic phase. The resistivity of this composite structure is determined to be approximately 20 times smaller than the precursor Mo thin film. Combining the structural details with the electrical properties it is deduced that excess C atoms not being able to diffuse into Mo2C matrix form approximately 17 nm large diamond like carbon (DLC) clusters interconnecting Mo2C grains at the very surface of the samples ending up resulting a Mo2C-DLC composite structure.