May 26, 2017 | 09:50 / Mühüm hadisələr
The Tl–I system has been studied using differential thermal analysis, X-ray diffraction, and emf measurements on TlI concentration cells. A more accurate Tl–I phase diagram is presented, according to which the compounds existing in the Tl–I system are TlI, Tl2I3, and TlI3. Thallium monoiodide melts congruently at 715 K and undergoes a polymorphic transformation at 440 K. The other iodides melt peritectically at 535 and 404 K, respectively. In contrast to what was reported previously, no compound of composition Tl3I4 has been obtained. Using experimental emf data, we evaluated relative partial molar thermodynamic functions of the TlI in alloys of the TlI–I system and the standard Gibbs free energy, enthalpy of formation, and standard entropies of TlI3 (−ΔG2980= 142.79 ± 0.73 kJ/mol, −ΔH2980= 135.37 ± 2.85 kJ/mol, and S2980= 263.3 ± 7.4 J/(mol K)) and Tl2I3 (271.39 ± 1.47, 262.40 ± 5.34, and 322.8 ± 13.2).
“The Tl–I Phase Diagram Revisited and the Thermodynamic Properties of Thallium Iodides” D. M. Babanly, L. F. Mashadieva, and M. B. Babanly “Inorganic Materials” 2017, Vol. 53, No. 5, pp. 519–524.