Acta chemica Scandinavica/Acta chemica Scandinavica. B, Organic chemistry and biochemistry/Acta chemica Scandinavica. A, Physical and inorganic chemistry/Acta chemica Scandinavica. Series B. Organic chemistry and biochemistry/Acta chemica Scandinavica. Series A, Physical and inorganic chemistry · 1962 · 66 citations · 0 references
Natural SciencesChemistryMaterials ScienceElectrochemistryInorganic ChemistryPhysical ChemistryChemical ThermodynamicsElectrochemical ThermodynamicsElectrode-electrolyte InterfacesMetal OxidesMixing ThermodynamicsCompositionOxide ElectrolytesOxide ThermodynamicsPartial Molar EnthalpyThermodynamic Data Of ElectrolytesThermodynamics Of Galvanic CellsUranium ChemistryUranium Dioxide
Electromotive force measurements on galvanic cells involving solid electrolytes were made at temperatures of 800 to 1200 deg C in order to obtain standard thermodynamic data for the mixing of UO2and oxygen gas. Due to purely anionic conductivity of the electrolyte, a direct evaluation of the relative partial molar free energy of oxygen in uranium oxide as a function of the O/U atomic ratio and temperature was possible. As a result, values for the partial molar heat and entropy of mixing and the corresponding relative integral quantities were calculated for the whole composition and temperature range investigated. Nonstoichiometry in the homogeneous UO2+xphase is discussed. The solubility of oxygen in this phase was found to be higher than previously known.