Synthesis of the titanium phosphide telluride Ti2PTe2: A thermochemical approach

The phosphide telluride Ti2PTe2 can be synthesised from the elements or from oxides in a thermite type reaction. Both ways have been optimised by consideration of the thermodynamic behaviour of the compound. Hence, the investigation of phase equilibria in the ternary system Ti/P/Te and of the thermal decomposition of Ti2PTe2 was necessary. This investigation was performed by using different experimental approaches as total pressure measurements, thermal analysis and mass spectrometry. The results were supported and further analysed by thermodynamic modelling of the ternary system. It was shown that Ti2PTe2(s) decomposes to Ti2P(s) and Te2(g) in six consecutive steps. The growth of single crystals of Ti2PTe2 is thermodynamically described as a chemical vapour transport with TiCl4(g) acting as the transport agent.

Graphical abstractOxygen partial pressure and electrochemical potential above the oxides of titanium, tellurium and phosphorus calculated at 1000 K, marked: level of equalisation of oxygen partial pressure.Figure optionsDownload full-size imageDownload as PowerPoint slide