Thermal stability of transition metal carbosulfides prepared by combustion synthesis

摘要

Tantalum carbosulfide and its intercalated compounds are soft layered materials that can easily be prepared by combustion synthesis. Titanium carbosulfide is a hard, brittle material with exceptional chemical stability. The thermal stability of these compounds has been investigated by heat treatments in air and inert atmospheres, as well as by differential thermal analysis in atmospheric air. It was observed that the substitution of Nb for Ta in tantalum carbosulfide leads to more exothermic reactions in the combustion synthesis, and DTA measurements revealed a small improvement of the high temperature stability in oxidizing environments. Our results show that titanium carbosulfide is stable in air up to 580 degrees C, whereas the richer in sulfur tantalum carbosulfide, stabilized by partial substitution of Nb, is stable up to 415 degrees C and does not decompose in an inert atmosphere at temperatures as high as 1100 degrees C. (C) 1998 Elsevier Science S.A. [References: 10]