Synthesis mechanisms and thermal stability of ternary carbide Mo2Ga2C

In this paper, the synthesis mechanism of Mo2Ga2C, a novel layered ternary carbide, was explored and understood. From thermal analysis and theoretical calculation, it was found that 650 °C was a suitable temperature to synthesize highly pure Mo2Ga2C. Higher temperature would results the decomposition of synthesized Mo2Ga2C. Based on this analysis and further analysis on synthesis time and materials ratio, 91.3 wt% pure Mo2Ga2C was successfully synthesized at 650 °C for 60 h from Mo2C/Ga = 1:5 mixture sealed in quartz-glass tubes. Thereafter, the thermal stability of the as-synthesized Mo2Ga2C was reported. In air, Mo2Ga2C started to be oxidized at 600 °C. The main oxidation products were MoO3 and Ga2O3. And MoO3 could be released due to vitalization at high temperature. The final oxidation product at temperature> 800 °C was GaO3. In Ar, Mo2Ga2C started to decompose at 700 °C. Mo2C and MoGa3 were main decomposing products. At 900 °C, another ternary carbide, Mo2GaC could be formed. At temperature> 1000 °C, the samples completely transformed to Mo2C and MoGa3.