Published online by Cambridge University Press: 28 February 2011
Enthalpies of formation of the perovskite-related oxides, La1.85 Sr0.15CuO4, YBa2Cu3Oy, with y = 6.93, 6.69, and 6.47 have been determined at 298.15 K by perchloric acid solution calorimetry. Enthalpies of formation and free energies of reactions with H2 O(g) and CO2 (g) have been evaluated. The partial molar enthalpy of solution of oxygen in YBa2 Cu3Oy has been determined and compared with values derived from measurements or the equilibrium partial vapor pressures of oxygen. The significance of the defect state thermochemistry in conductivity is identified.
Permanent address: Department of Chemistry and Biochemistry, Illinois Benedictine College, Lisle, IL 60532.
Work performed under the auspices of the Office of Basic Energy Sciences, Division of Chemical Sciences, U. S. Department of Energy, under contract number W-31–109-ENG-38.