Synthesis mechanisms and thermal stability of ternary carbide Mo2Ga2C

Abstract In this paper, the synthesis mechanism of Mo 2 Ga 2 C, 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 Mo 2 Ga 2 C. Higher temperature would results the decomposition of synthesized Mo 2 Ga 2 C. Based on this analysis and further analysis on synthesis time and materials ratio, 91.3 wt% pure Mo 2 Ga 2 C was successfully synthesized at 650 °C for 60 h from Mo 2 C/Ga = 1:5 mixture sealed in quartz- glass tubes. Thereafter, the thermal stability of the as-synthesized Mo 2 Ga 2 C was reported. In air, Mo 2 Ga 2 C started to be oxidized at 600 °C. The main oxidation products were MoO 3 and Ga 2 O 3 . And MoO 3 could be released due to vitalization at high temperature. The final oxidation product at temperature> 800 °C was GaO 3 . In Ar, Mo 2 Ga 2 C started to decompose at 700 °C. Mo 2 C and MoGa 3 were main decomposing products. At 900 °C, another ternary carbide, Mo 2 GaC could be formed. At temperature> 1000 °C, the samples completely transformed to Mo 2 C and MoGa 3 .