Thermodynamic properties of the UO2-ZrO2 system studied by the isothermal mass spectrometric vaporization method

The Knudsen effusion high-temperature mass spectrometric method was used to study the vaporization processes and thermodynamic properties of the UO2-ZrO2 system in the temperature range 2200-2650 K. The work was carried out with the MS 1301 mass spectrometer developed for studies of physico-chemical properties of inorganic substances at high temperatures. Vaporization of the solid solutions containing 0.02-0.45 mol fractions of UO2 was done using tungsten cells. The vaporization processes and the chemical potentials of ZrO2 in the UO2-ZrO2 system and in the Y2O3-ZrO2, Lu2O3-ZrO2 and HfO2-ZrO2 systems, available in the literature, were discussed from the point of view of the acid-base concept. (orig.)