A novel process to prepare MoSi2 by reaction between MoS2 and Si

In this study, a thermodynamic analysis of the reaction between MoS2 and Si was performed, which indicated that when the molar ratio of MoS2 to Si is 1:4, the final products were composed of SiS and MoSi2, without other solid phases, in the temperatures range of 0 °C-1700 °C. The reaction between MoS2 and Si powders with a MoS2/Si molar ratio of 1:4 was investigated in the range of 800 °C-1600 °C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the phase composition and microstructure of the products, respectively. The content of sulfur in MoSi2 product was measured using an infrared carbon-sulfur analyzer. It was found that pure MoSi2 can be successfully synthesized in the temperature range of 1100 °C-1600 °C after reacting for 2 h with very little sulfur residual. Meanwhile, gaseous SiS was also generated and escaped from the MoSi2. It was also found that the reaction rate between MoS2 and Si was very slow at 800 °C and 900 °C. The microstructural analyses indicated that grain size of the MoSi2 product increased with increasing temperature.