Talk:Scandium(III) sulfide

Synthesis temperature > decomposition temperature?[edit]

How can Sc₂S₃ be synthesized at >1550°C if it decomposes above 1100°C? This is only possible if the lower sulfides are formed in the described synthesis process, and then react with further sulfur (or hydrogen sulfide) upon cooling, ultimately producing Sc₂S₃. But the article also describes that heating scandium and sulfur together only produces ScS and never Sc₂S₃, implying that Sc₂S₃ cannot be produced by reacting lower scandium sulfides (like ScS) with further sulfur. --79.243.249.158 (talk) 20:27, 3 September 2013 (UTC)[reply]

Sorry, I confused scandium oxide with elemental scandium ... but there's still the question how to yield Sc₂S₃ at temperatures above its decomposition temperature... --79.243.249.158 (talk) 20:32, 3 September 2013 (UTC)[reply]

Good catch. The prep gives crappy samples for the reasons that you indicate - it is unstable at 1550 C. Limiting decomp is the fact that the prep is conducted under flowing H2S. To obtain good samples, they transported the material at 950 C, well below the decomp temp. --Smokefoot (talk) 23:02, 3 September 2013 (UTC)[reply]