H 65 High-Temperature Equilibrium between YBa2Cu 3- xCoxO 6 + delta Solid Solutions and Oxygen / M. V. Patrakeev, E. B. Mitberg, A. A. Lakhtin, I. A. Leonidov, V. L. Kozhevnikov, V. I. Voronin // Inorganic Materials. - 2000. - Vol. 36, № 5. - P. 474-478 : il. - Bibliogr. : p. Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): РАСТВОРЫ ТВЕРДЫЕ -- ТИТРОВАНИЕ -- КИСЛОРОД -- КУПРАТЫ КОБАЛЬТСОДЕРЖАЩИЕ Аннотация: The equilibrium oxygen content of YBa2Cu3_ xCoxO6 + 8 (0.2 < x < 0.8) solid solutions was determined by coulometric titration at temperatures in the range 600-850~ and oxygen pressures 1 < Po2 < 105 Pa. The partial enthalpy and entropy of oxygen dissolution were evaluated as a function of composition. The thermodynamic functions were found to change sharply near the high- and low-oxygen limits of the solid solution. The results are interpreted in terms of a quasi-chemical model considering three inequivalent oxygen sites in the basal plane |