ChemInform Abstract: Thermodynamic Study of the Systems PrSe_2.00—PrSe_1.50 and GdSe_1.875—GdSe_1.50.

Abstract

Equilibria E 4000Thermodynamic Study of the Systems PrSe2.00-PrSe1. 50 and GdSe1.875-GdSe1.50. -The total pressure over high-quality crystals of PrSe 2.00 and GdSe 1.875 is measured in the temperature range 675-1296 K. The p-T-x diagrams show that the regions between the boundary compositions PrSe2.00 and PrSe1.80, GdSe1.86 and GdSe1.77 which were previously described as non-stoichiometric, consist of discrete stoichiometric phases such as PrSe1.90, PrSe1.85, PrSe1.80, and GdSe1.85, GdSe1.80, GdSe1.71, respectively. The standard heats of formation and the absolute entropies are estimated for each polyselenide. -(CHUSOVA*, T. P.; ZELENINA, L. N.; VASILYEVA, I. G.; GRAF, C.; DOERT, T.; J. Alloys Compd. 452 (2008) 1-2, 94-98; Nikolaev Inst. Inorg. Chem., Sib. Branch, Russ. Acad. Sci., Novosibirsk 630090, Russia; Eng.) -W. Pewestorf 23-008